Modern Gun School Unit 1 - Advanced Gunsmithing Program PDF

ADVANCED GUNSMITHING PROGRAM Study Unit 1 Gunsmithing Since 1946 About the Editorial Staff Consultant/Program Reviewer: Harry G. Walters III Harry “Skip” Walters has over 30 years’ experience working as a Gunsmith, Engineer Tech- nician and Model-maker. Skip currently works as a Master Gunsmith at SARCO Inc., a retail and wholesale firearms shop that specializes in hard-to-fnd repair and replacement gun parts. He graduated from the Master Gunsmithing program offered at the Pennsylvania Gunsmith School and has a certificate in Ordinance Technology. Skip's extensive Gunsmith training and real-world experiences offer valuable insight and instruction to both Modern Gun students and support staff. Editorial Reviewer: Paul Grumbein Paul Grumbein holds a Bachelor of Science degree in secondary education and has over 15 years of experience in distance education. As a professional educator, he focuses on the growth and development of new programs. At Direct Learning Systems Inc., his responsibilities include leadership, team building, and support. As a lifelong gun enthusiast, Paul’s avocations include recreational shooting and hunting. Modern Gun School Layout/Editorial Staff: Stacy Feifel, Valerie Behrle B.S., M.Ed. Copyright ©2023 Modern Schools of America, LLC. All rights reserved. No part of the material protected by this copy-right may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the copyright owner. Requests for permission to make copies of any part of the work should be mailed to Copyright Permissions, Modern Schools of America, LLC. 1000 N. West Street Suite 1200, Wilmington, DE 05478 Printed in the United States of America. Modern Gun School Founded in 1946 Student Service Center P.O. Box 3773 Allentown, PA 18106 Congratulations on your decision to become a better gunsmith! Thank you for choosing Modern Gun School to help you reach this goal. Before you begin reading your lessons, take a few minutes to read the following instructions. Doing this will help us provide you with better service. The following steps will help you complete this course successfully: 1. Carefully read the course introduction. The introduction offers valuable information for com- pleting this course. It also includes a Glossary of Gunsmithing Terms which provides an alpha- betical list of defined terms used in the course lessons and in materials furnished by suppliers, manufacturers, and dealers. 2. Read the material in the order it is presented. 3. Each unit has several lessons. Every lesson ends with a self-check to make sure that you understand what you have read. Once you have completed the self-check, review your answers with the suggested answers provided at the end of that unit. Then move onto the next lesson. 4. Once you have read all of the lessons, completed and reviewed the self-checks, and feel confi- dent you understand the material, take the unit examination online at www.mgs.edu. 5. If you are manually completing your exam, mark your answers carefully onto the answer sheet provided, and remember to make a copy of the answer sheet. Modern Gun School is not responsi- ble for lost answer sheets. Return your exam answer sheet in the envelope provided via First Class or Priority Mail. The date MGS grades your exam will be the completion date recorded for that exam. Modern Gun School will grade your exam and return a grade report to you. 6. This course includes hands-on projects using several different techniques relative to gun repair. All projects, once completed are to be returned along with your mail back project sheet to MGS for evaluation. All project requirements must be met in order to receive your diploma. 7. In addition, the supplementary items included in this course present different sources of in- formation such as gunsmithing tips, articles relative to the firearms industry, and vendor catalog contact information. 8. If you have any questions, please call our student service center at 800-493-4114, Monday - Friday, 8:30 a.m. – 4:30 p.m. (EST). Sincerely, Zeke Stout Director Course Introduction Getting Started Welcome to Modern Gun School! This guide provides you with our contact information, submitting examinations, our grading system, retesting, payments, change of address and a course overview. While we don’t know much about you personally yet, we do know a great deal about our students. We know they are eager to learn more about repairing guns, willing to work hard and are determined to do the best job possible. We are sure you share these same qualities! We have arranged each lesson to help you move easily through your studies. These lessons should be thought of as the beginning of your own personal library on guns and gunsmithing. Each unit has lessons that end with a self-check. Every unit concludes with a multiple choice exam. Once you have completed the lessons and self-checks and feel confident you understand the material, take the unit exam and return it to Modern Gun School for evaluation. Getting Help Sometimes even the best students need help. Our staff tries to anticipate when you might have trouble and provides a little extra support within the study materials. In spite of these efforts, we know that you may need to reach us to help you over a difficult spot. There are four ways to reach our staff: 1. Email us at [email protected] us what lesson you are studying, the page number, and how we can help. Please include your student ID number. Responses generated from our staff are typically sent by the next business day. 2. Call the school Monday-Friday during the hours of 8:30 a.m.- 4:30 p.m. (EST). If you call after hours please leave a message with your name, student ID number, lesson, and page number where you are having trouble. Also, let us know the best time to call you back. We will get in touch with you as quickly as we can. You can call us toll free at 800-493-4114. 3. If you choose to mail your questions, please submit one of our Request for Consultation forms, located at the end of each unit. Mail to our address at: Modern Gun School Student Service Center P.O. Box 3773 Allentown, PA 18106 4. You can Fax your request for help to: 855-530-3652. Our staff is here to help you! Introduction v Bench Notes: Throughout the course, you will find "Bench Notes"-- marked by text boxes with dotted line bor- ders. These "Bench Notes" offer direction, additional tips, gun features, and articles for you as a student. At times. these notes introduce the supplementary information that will follow. Examinations Since you schedule your own examinations, you should not feel any pressure. You should take your exams when you are ready. Give yourself the best chance for a good grade by following these simple steps: 1. Review your notes, vocabulary lists, Self-Checks, and highlighted reading. 2. Follow the directions carefully. Be sure you understand what you are supposed to do for each question. 3. All of your exams are “open book.” We encourage you to go back to your lesson material and look up any answers to problems or questions you do not know. Open-book exams not only help you to learn, but also to remember the material you have studied. 4. When you are ready, take your exam in the Online Student Center. Be sure to properly enter the exam number exactly as it is listed at the beginning of the exam at the end of this Study Guide. 5. When you receive your Grade Report, make sure you take the time to review any questions you may have answered incorrectly. The evaluator’s references will help reinforce your learning. If you wish to discuss a particular exam item or answer, please contact Student Services. If you receive a failing grade, it is especially important to review the evaluator’s references before taking a retest. You are only eligible to take one retest for a failed exam. Academic Honesty You are taking this course because you want to learn, so cheating should not be an issue. You are in a class of one. Every part of this course is planned to help you understand the subject matter. The exams are part of this process.You may use your material as a reference to help you take the examinations. In most cases it will be a guide to the right answer. Grading System Each examination is viewed as a learning tool and as a measurement device. In addition to grading examinations, we will provide reference pages to locate answers to any questions answered incorrectly. Students should not delay their studies while their examinations are being graded, but vi Introduction they should stop, review, and re-study critical areas when each Grade Report is returned. This review of the examination and the use of the page references are a vital part of the instructional system of MGS. The individual examinations are scored on a straight numerical basis. Once a student has completed all of the examinations in a course, the final grade is determined by averaging all the lesson grades together. The equivalent letter grade is determined by the following scale: Letter Grade Numerical Equivalent A Excellent 94-100 B Good 86-93 C Satisfactory 78-85 D Passing 70-77 F Failing Below 70 Retesting Students who receive 69 percent or lower on any exam will be eligible for one retest. Please take the time to review the questions that you missed and the reference pages provided before taking a retest. The MGS policy is that any student who passes a retest may not score higher than 70%, no matter what grade they received on the retest. Students who fail to achieve a minimum passing grade (70%) on a retest will receive the higher grade of the two failed exams and the score will be calcu- lated into the final average. No further retesting is available. Academic Records Modern Gun School complies fully with the Family Education and Privacy Act of 1974, as amended. This act is designed to protect the privacy of educational records, to establish the rights of students to inspect and review their educational records, and to provide guidelines for the correction of inaccurate or misleading data through informal and formal hearings. A student who believes that an error has been made in their grade must initiate contact with the school within 30 days from the date the grade was posted. Failure to act within 30 days disqualifies the student from further consideration of the matter.The student is responsible for reporting any other type of error on their academic record. Modern Gun School is not liable for unreported errors on student records. Completion Documents Upon successful completion of the program and satisfaction of all financial obligations, the student is awarded a transcript and a diploma. In order to earn a diploma, a student must achieve a minimum average of 70% in the course. Modern Gun School will not issue any completion docu- ments until all financial obligations are satisfied. Introduction vii Transcripts One official transcript of record is furnished to the student at the conclusion of the course with- out charge. For each additional transcript, a fee is charged. No transcripts are released for students who have failed to meet their financial obligations to MGS. Change of Name or Address In order to receive information essential to your studies, students must report all changes in name and/or address to MGS. All changes should be reported promptly to [email protected] or 800-493-4114, in order to reflect such changes on your school records. Use of “Change of Address” fields within the MGS invoice or an exam sheet is also permissible. A change in name will require proof, such as a marriage license. Course Interruption Should a student desire a temporary leave of absence from the program, a request should be sub- mitted in writing to MGS. One three (3) month leave of absence will be granted for good cause. A leave of absence does not extend the required time for completion nor suspend the tuition payment plan. Payments Each month, upon receipt of a payment and depending upon the plan selected, the student will receive the next shipment. We do not make shipments until payments have been received. You have been sent a copy of your Enrollment Agreement explaining the billing cycle you have chosen. Please remember that the school reserves the right to discontinue the training of any student who breaks the terms of payment under the agreement. Submitting Examinations Online To submit your exams online, go to www.mgs.edu, click on the Student Login button, register, and login with the the username and password you receive in your welcome email. Mailing Instructions for Examination Answer Sheets Before submitting an Examination Answer Sheet, make sure that it has the following: 1. Your answers to all the examination questions 2. Your Name, Student ID Number*, and Address * Your Student ID number is found in your welcome letter or email To Mail: 1. Use the return envelopes provided (more than one exam or assignment may be sent in an envelope) and mail to: Modern Gun School Student Service Center P.O. Box 3773 Allentown, PA 18106 viii Introduction 2. Make a copy of the answer sheet to keep for your records. 3. It is very important that you complete the return address information on each envelope. This includes your name and address. 4. Mail each exam as soon as it is completed using first-class postage. When You Receive Each Lesson If you find any of the materials are defective or missing, CALL US IMMEDIATELY at 800-493-4114, Monday through Friday between 8:30a.m. and 4:30 p.m. (EST), or leave a mes- sage after hours on our voice mail. How to Study You are probably eager to get started. Like any independent student, you determine the pace at which you complete the lessons. You may go as fast as you are comfortable. A steady pace of 1-2 hours daily works better than fewer sessions of many hours. Here are some suggestions for organizing your study habits. If you follow these tips, you will improve your chances for success. 1. Do not start reading your lessons until you have read the introductory material in this section. 2. Skim the lessons to get a feel for what your course covers; it will help set your frame of mind. Skim by reading the headings and subtopics. Research has shown that students who skim their lessons, before studying them, read 24 percent faster than those who do not. Furthermore, they remember more of what they read. Do not be afraid to mark up your lessons with questions and comments. 3. Question: Turn every heading into a question. This will help you discover what you will be learning. Take notes after you have answered each question. Notes give you the chance to express in your own words what you thought about the assignment. 4. Read: You may wish to underline key sentences or to make a note or two in the margin. Read with a colored highlighter in hand. Highlight all new vocabulary words and major ideas. Most paragraphs contain a principal thought or conclusion. Find that thought! It may be a single sen- tence or part of a sentence. Highlight it, but don’t overdo it. No more than 15 percent of each page should be highlighted. If you come across a difficult section, read it over a second, and even a third time. Rereading can help you understand material that seemed confusing at first. Take your time. 5. Study: Review the material that you underlined or highlighted in your lessons. Reread any notes. Review anything that you did not understand. 6. Examinations: After you have finished reading and reviewing your lessons, take the examina- tion. Take your time and choose your answers carefully. When and Where to Study You may be wondering whether you have the self-discipline to complete this course. Many people doubt themselves when they begin something new. However, you can be successful in your studies with the right attitude. The trick is to develop good study habits. Introduction ix A habit is something you do automatically, without thinking about it. In other words, a habit is second nature to you. How do you acquire a habit? By repetition. A good way to begin developing excellent study habits is to pick a time and a place to study. Pick a quiet place to study and choose a time of day when you are awake and at your best. Try to study in this place at the same time each day. Ask yourself these questions when choosing a place to study. 1. Can I use this location on a regular basis? 2. Can I eliminate distractions from family, friends, the television, and the phone? If you have an answering machine, let it take the calls for you while you are studying. 3. Does the area have good lighting without glare? 4. Is there enough room to file study materials so I won’t lose time looking for them? MGS will supply all of the necessary lesson study materials. You will need a pen, a highlighter, a few pencils, and some paper. Setting up a Study Schedule You are much more likely to develop good study habits if you set up a study schedule. You might feel that you will complete the course just because you are interested in the subject. This is a common mistake. Wanting to do something is not the same as actually doing it. Setting up a study schedule will help you get the work done. Stick with your study schedule until it becomes a habit. You have 24 months to complete this entire course. Here are a few hints for setting up an effective study schedule. 1. A study schedule is serious business; it is a promise to yourself. Set up a schedule you can stick to. Be realistic; leave ample time for family and job responsibilities. Each study session should be long enough to allow you to complete one or two sections, but short enough that you won’t put off studying. 2. Be consistent in choosing the days and hours when you will study. It is not important which days you pick, but they should be the same days each week. Ask yourself, “What are my best studying hours? When am I most alert?” Set your study priorities with this thought in mind. Let your family and friends know when your study periods are so they can schedule their social activities around them. 3. Try to spend eight to twelve hours a week studying. Two hours a day is what the average student can handle for an extended period of time. The minimum time you should plan for is six to eight hours of study per week. If you let too much time pass between study periods, you will have to spend time rereading to remember what you learned in your last study session. 4. Reward yourself for a good study session. For example, if you plan to study in a two-hour block, take a ten-minute break after the first hour. You will go back to your studies refreshed and with determination. Do something you enjoy after you have completed your studies for the day. 5. We are all subject to periods of fatigue and frustration, when we feel like “throwing in the towel.” Besides your final goal, it is a good idea to set up short-range objectives. Short-range ob- jectives seem possible to achieve and can serve as a motivator each time you achieve one. x Introduction 6. Allow for emergencies and the necessity to change your schedule. Conflicts are bound to happen and you may have to reschedule a study session. Don’t let this happen often; don’t look for reasons to do something else. When you must miss a study session, plan a definite day and time to make up the hours you missed. 7. Finally, remind yourself that you have a purpose, a long-range goal to achieve. You want a chal- lenge, the opportunity to repair guns, and perhaps, the chance to operate your own business. Making consistent, steady progress is the key to success! Learning Strategies How do you usually study for an exam? Do you take your time and study a little bit each day, or do you try to cram it all in the night before the test? Studying a little bit each day is definitely a better learning strategy. A learning strategy is a plan that you can use to learn new material. Learn- ing strategies can help you study and do well on examinations. In this next section, we present some learning strategies that have helped many students succeed. The SQ3R Learning Strategy SQ3R is an acronym that stands for Survey, Question, Read, Recite and Review. This learning strategy was developed in the 1940s and has helped many students over the years. Survey. According to SQ3R, you should begin reading a lesson by surveying it. When you survey, you look the lesson over carefully. Read the title of the lesson. Read any introductory material. Read each of the headings and subheadings. Note the way the lesson is organized. Major headings, the largest headings, refer to major ideas. Minor headings, or subheadings, refer to ideas that are related to each major heading. If you were to make an outline of a lesson, each major heading would be a major idea on the outline; minor or subheadings would be underneath major headings. Note any words that are italicized or in bold. These are usually new terms. Lastly, read the self-checks or examination at the end of the lesson. For this program, reading the lesson examination is not cheating! Remember that the examinations in this program are open book, so you can use your material to help you answer the questions correctly. Surveying the examination will help you note important concepts within the lesson. Question. After you survey a lesson, ask yourself questions about it, such as, “What is the main idea of this lesson?” and, “What is the meaning of this term?” When you read the lesson, look for answers to your questions. Read. Now you are ready to read each section in the lesson. You’ll be much more prepared to read and learn the information in a lesson if you first survey it and ask questions about it. Read one section at a time. Begin at a major heading and continue until you get to the next major heading. If the material you’re reading is complicated, you might want to stop after each minor Introduction xi or subheading. Reading too much material at one time can be overwhelming. Learning is easier if you break your lessons into smaller segments. Be sure to take notes while you read. Don’t be afraid to write in your materials or lessons. Jot down important ideas in the margins. Use a highlighter to highlight important information. Recite. After you read a section, recite important ideas. When you recite, you repeat information out loud. Recite the definitions to important terms along with any other important information. Recite the important information in a section before reading the next section. Review. After you read a lesson or a section of a lesson, review what you have read. When you review, focus only on important information. Don’t reread every word, only the information you have highlighted. Review your notes and the entire lesson before completing the examination. You may have to review a section many times before you feel confident enough to complete the examination. Memory Tricks Suppose you were asked to memorize a list of terms. How would you go about doing this? Would you jot down the terms on the side of one page and the definitions on the other? This way, you could cover up the definitions with a sheet of paper while you were trying to learn them. You might also create flash cards to help you learn the meaning of the definitions. Both of these are effec- tive learning strategies. The following are some memory tricks that you can use to help you remem- ber new information. Grouping information. People usually have little trouble remembering details about things they enjoy or things that are important to them. A chunking method is when we commit ideas to memory; we are actually processing the information as individual concepts or items. Chunking uses this to our advantage, by taking multiple items and combining them into a single item. This allows us to re- member much larger amounts of information by having one single item contain even more informa- tion within. For example, you probably remember the phone numbers of your five closest friends or relatives. You might also know your friends’ birthdays. But if a teacher gave you a list of information to memorize, you might have trouble learning it. Memorizing such material is easier if you group items in the list according to their common characteristics. Mnemonics use words or abbreviations to compress lists of information into shorter bits that are easier to remember. Although it can be easiest to remember those things that you understand well, sometimes you must rely on rote memory. The following techniques can be used to facilitate such memorization. 1. Acronyms. You form acronyms by using the first letter of each word in the group to form a new word. This is particularly useful when remembering words in a specified order. Acronyms are very common in ordinary language and in many fields. Some examples of common acronyms include NRA (National Rifle Association), NSSF (National Shooting Sports Foundation), and ACLU (American Civil Liberties Union). xii Introduction 2. Sentences/Acrostics. Like acronyms, you use the first letter of each word you are trying to remember. Instead of making a new word, though, you use the letters to make a sentence. Here are some examples: My Dear Aunt Sally (mathematical order of operations: Multiply and Divide before you Add and Subtract) 3. Rhymes & Songs. Rhythm, repetition, melody, and rhyme can all aid memory. Are you familiar with Homer's Odyssey? If you are familiar with the book, then you know that it is quite long. That is why it is so remarkable to realize that this, along with many ancient Greek stories, was told by storytellers who would rely solely on their memories. The use of rhyme, rhythm, and repetition helped the storytellers remember them. Multiple-Choice Tests You will be asked to take a multiple-choice exam at the end of each unit in this program. Ear- lier you learned that you should survey each lesson examination before you read the lesson and that you should not take an examination until you have reviewed the material in the lessons several times. The following are some additional tips for taking multiple-choice examinations: Answer each question in your head first. If you know the answer to a question, you will be less likely to choose the wrong answer. Read the stem—the part that asks a question—several times to be sure you understand it. Reading a question too quickly may cause you to answer it incorrectly. Circle words such as not, except, or all. These words change the meaning of a question. For ex- ample, if the question asks, “Which of the following is not true about gun safety?” Circle the word not. If the answer calls for a sentence completion, eliminate any answer choices that do not complete the sentence correctly. The multiple-choice examinations in this program are open book, so look back at your notes and your lesson materials whenever you are unsure of an answer. Keep in mind that just because an examination is open book does not mean that it is easy. You may not be able to find every answer in your lesson materials. Some questions may require you to think about what you have learned and choose the best answer. Now that you have learned some helpful study strategies you are ready to begin your course. We look forward to receiving and reviewing your examinations! Introduction xiii xiv CONTENTS Modern Gun: Unit 1 UNIT LEARNING OBJECTIVES I GLOSSARY OF GUNSMITHING TERMS III-XIX LESSON 1 Where and How to Begin...............................................................................................................1.38 Smith and Wesson Chief Special.............................................................................................4 Self-Check....................................................................................................................................16 LESSON 2 Safety- First, Last and Always.....................................................................................................19.45 Colt M-1911...........................................................................................................................24 Self-Check....................................................................................................................................41 LESSON 3 Beginning Your First Project.......................................................................................................43.38 Smith and Wesson Military and Police..................................................................................50 Gun Laws and Gun Repairmen....................................................................................................65 Self-Check....................................................................................................................................66 SELF-CHECK ANSWER KEY 68 UNIT 1 EXAMINATION 71 REQUEST FOR CONSULTATION 75 UNIT 1 LEARNING OBJECTIVES When you complete Unit 1 you should be able to: Define the essential safety precautions for any type of gunsmithing List the basic rules for effective firearms handling Explain the provenance , assembly and disassembly of a Smith & Wesson.38 Chiefs Special Revolver Explain the provenance, assembly and disassembly of Colt Government Model 1911- Caliber.45 Identify the model specifications on Government Model Calibers: 9MM.38 Super Auto.45 ACP Start a new gun repair project Assembly and disassembly of the.38 Smith and Wesson Military and police revolver I II Glossary of Gunsmithing Terms Glossary of Gunsmithing Terms ACP: Stands for "Automatic Colt Pistol". Used ANVIL, PRIMER: A small pointed piece of to designate certain cartridges first chambered (in metal inserted in a primer on which to crush the USA) in Colt automatic pistols –.25 ACP,.32 the priming composition thus causing the spark ACP,.380 ACP,.38 ACP,.45 ACP. which ignites the powder. See PRIMER. ACCURIZE: Improving the accuracy of a ANNEAL: To anneal steel or other metals is handgun, usually an auto pistol, by reducing to render it soft. It is usually accomplished by tolerances between parts. heating it to a red color and allowing it to cool gradually. ACTION: Action of a rifle is the actual firing mechanism or the complete mechanism of the ASSAULT PISTOL: A high-capacity, full firearm exclusive of the barrel and stock. It is the automatic firearm styled like a sub-machine means by which the gun is loaded, and which gun, but having a pistol-length barrel and secures the cartridge in the chamber against lacking a fixed buttstock, such as a PDW discharge to the rear. -personal defensive weapon- (i.e. Cooray MI1/ CZVZ61 Skorpian). ACTION, BOLT: A breech action of a rifle which is opened, closed and operated by means AUTOMATIC: A term commonly used for a of a bolt, the latter having a handle. self-loading firearm. A firearm is truly auto- matic only when it continues to fire as long as ACTION, LEVER: A breech action which is the trigger is held back. Full automatic firearm opened, closed and operated by means of a lever possession without proper documentation is formed as a rearward extension of the trigger illegal in this country. guard. BALANCE: The balance is literally that point ACTION, PUMP: A breech action which is between butt and muzzle where a gun bal opened, closed, and operated by means of a slid- ances when rested on a fulcrum. However, this ing fore-end which is formed into a convenient is not the popular understanding of the term. handle for this purpose. Also termed slide Neither is it an entirely popular understanding action, falling block, swinging block, rolling that a gun balances properly when the point of block, break, gas (semi & auto) recoil, semi-auto balance is midway between the points where straight blow-back (semi & auto), delayed blow- the hands naturally hold it in shooting. In most back (semi & auto). cases, balance is understood to mean the feel it gives to the shooter in handling the gunthat is, AMMUNITION: Cartridges, shotgun shells or whether correctly balanced or either muzzle both. light or muzzle heavy. AMMUNITION, METALLIC: Cartridges BALLISTICS: The theory of the motion of loaded in metallic shells or cases. Used in the projectiles. The American shooter loosely trade as referring to rifle and pistol cartridges to considers "ballistics" to mean the data relative distinguish them from shotgun shells, which are to the velocity, energy, trajectory, and penetra- usually loaded in cases made principally of paper tion of a cartridge. or plastic. 4 Glossary BALLISTICS, EXTERIOR: The theory of BLOWBACK: An operation system in the motion of the projectile from the gun to the self-loading firearms in which the slide or target. breechblock is driven to the rear by direct gas pressure on the cartridge case head. BALLISTICS, INTERIOR: The theory of the motion of the projectile in the firearm. BORE: The hole through the barrel of a firearm. In a rifle the bore is the hole after it has been BALL POWDER: -see OLIN BALL POWDER. drilled and reamed, and before rifling; that is, the bore diameter of a rifle is the diameter BARREL: Steel tube of a firearm through measuring to the top of opposite lands. Bores are which the projectile is driven. It directs the usually measured in fractions of an inch and in projectile toward its target. millimeters. The groove diameter is the diameter to the bottom of opposite grooves. See CHOKE BARREL LENGTH: Per Federal (with regard to shotguns). Firearms Act of 1935 and the most recent amendment which became effective on July BREECH: The rear end of the bore of a firearm 1, 1960, no rifle can have a barrel length less where the cartridge is inserted into the chamber. than 16 inches or a shotgun have a barrel length less than 18 inches in length overall. Any rifle BREECH BLOCK: The steel block which or shotgun that can be converted to an overall closes the breech of a firearm, sustaining the length less than 26 inches is illegal. head of the cartridge when the gun is fired. BASE WAD: A compressed paper filler inside BREECH BOLT: Part of the action which the head of a shot shell, used to keep the pow- closes the breech. The part which locks the der in position in front of the flashing end of cartridge in place. The word "Bolt" is commonly the primer. Latest loadings of Super-Speed and applied to this part in bolt-action, lever, pump Super-X 12-16-20 gauge shells do not have base rifles and semi-automatic rifles. In some instances wads. Both have the new, ultra strong, all plastic, such as falling-block, single-shot actions, the compression-formed cases. corresponding part is called a breech-block. BREECH PRESSURE: The peak of the rear BEAVERTAIL: A fore-end grip of a shotgun or a target rifle which is made wider than a standard ward pressure exerted by the detonated powder gas fore-end. From the shape of the tail of a beaver- in the bore of a firearm when a given cartridge is wide and flat. fired therein. It is expressed in pounds per square inch, and is measured with a pressure gauge. BENCH REST: A bench table, arranged so as BULLET: The projectile for a firearm. to provide mechanical rests for the forearm or Projectiles are made in many shapes, sizes and of barrel of a rifle and a marksman's elbows, the many different materials. The most common type marksman being seated at the table. Used for of bullet is the regular, solid cast bullet made from accurate firing in testing a rifle or ammunition,or lead or some alloy of lead. A regular-jacketed bul- both. let consists of a jacket made of copper or an alloy of copper or steel with a lead core. Jacketed bul- BEVEL BASE: Any bullet design in which lets are made in several types such as hollowpoint, there is a slight bevel between the base and the softpoint, or full metal jacket. Soft and hollow bearing surface proper. pointed bullets were sometimes called dum-dums. BIG BORE: See "large bore." The term "dum-dum" applies more or less to bul- lets that will upset or expand upon impact. Some jacketed bullets are made with bronze or steel Glossary 5 points and special types of bullets are made which Such caps are usually referred to as percussion are called armor-piercing or incendiary. caps instead of caps. BULL GUN: A target rifle with extra heavy barrel. CARBURIZING: (carbonizing) Heat treatment of low carbon steel to introduce carbon into BUTT: Part of the gun stock which comes in the surface which produces a hard skin when contact with the shoulder of the shooter. quenched. BUTT PLATE: Plate used to cover the end or CARBINE: A short-barrel rifle commonly used butt of the stock. It is made from various types by troops on horseback. Still in military use in of material such as metal, horn, plastic or rubber. varied applications. When made of soft rubber it is termed a recoil CARRIER: The mechanism in a magazine or pad. repeating firearm (not a revolver) which carries CALIBER: Actual diameter of the bore of a the shell or cartridge from a tubular magazine rifle. It is commonly measured in two ways:1. By into a position to be pushed into the chamber by actual bore diameter; 2. By the groove diameter. In the closing of the breech bolt. America and England it is expressed in decimals of an inch, and in Europe it is expressed in mil CARTRIDGE: The fixed ammunition of limeters. metallic type for a firearm. A cartridge is an assembly of (1) case, (2) primer, (3) powder CAM: In guns, usually takes the form of a charge, (4) bullet or projectile. Therefore, the slanting surface which, when rotated, will move word cartridge applies to the four component a contacted part backward or forward. Cams are parts assembled into one element. commonly used in firearm actions to accomplish the actual locking operation or to accomplish CAST-OFF: Distance a stock is offset to the other functions such as cocking. right from the line of sight or from the axis of the bore, away from the face of a right-handed CANNELURE: A depression or groove rolled shooter. Many double guns are slightly cast off into a bullet or cartridge case. Cannelure in a but few are cast on. bullet can be plain or knurled and it sometimes functions to crimp the cartridge down to retain the CAST-ON: Term used when the stock offset bullet in place. Another function is to help hold is to the left. Cast-off is commonly used for the the lead core within the jacket. A cannelure on right-handed shooter; cast-on for the left-handed a case is simply a groove rolled in the neck at one. the proper point to keep the bullet from sliding CENTER-FIRE: Term applies to a firearm too far into the case. Entirely lead bullets have which uses a cartridge with the primer in the numerous cannelures for the retention of grease center of the case head. or lubricant. CENTER FIRE CARTRIDGE: A cartridge CANT: Leaning of a rifle to one side or the other having the primer containing the priming compo so that the sights are not in a truly vertical plane. sition inserted in the center of the head of the Canting a rifle to one side causes its bullet to shell or case. strike the target on the opposite side of the cant and slightly high. CENTER PUNCH: Punch with a short sharp point for making marks on metal. The 600 CAP: Metal covering for a pistol grip or the end "center punch" is used to enlarge marks made of a forearm. It is also used in connection with with the 300 "prick punch" when precision percussion caps used for detonating muzzle- layout is required. loading firearms of the percussion-cap type. 6 Glossary CHAMBER: Enlarged recess in the breech of a COCK: To pull the hammer or firing pin of a firearm which is provided to accept the cartridge gun back to full-cock so that the firearm is ready or shell. to fire. A firearm with a visible hammer usually has half-cock and full-cock positions. CHASERS: Special tools for cutting threads. COCKED AND LOCKED: The practice of CHECKERING: Applies to diamond-shaped carrying a self-loading pistol with a round in patterns cut in wood or metal parts for the the chamber, the hammer cocked and the safety purposes of minimizing slippage, and for the engaged. purpose of ornamentation. COCKING PIECE: Piece attached to the CHEEK PAD: A leather attachment with rubber projecting end of the firing-pin in bolt-action padding inside which is provided to raise the rifles. Cocking pieces are normally made in two comb of a shotgun or rifle which the shooter styles, head and headless. A good example of finds too low to fit him satisfactorily. the head-type is the 1903 Springfield, which has a large head or knob on the large end of the CHEEK PIECE: Projection or raised portion cocking piece which can be grasped with the of a gun stock which affords a better rest or more thumb and forefinger, thus enabling the shooter surface for the cheek of the shooter at the time of to manually cock his rifle. The headless type firing a rifle or shotgun. of cocking piece is either plain or has a small groove or some provision for insertion of a CHOKE: The constriction in the muzzle end of a cartridge rim or screwdriver or some other tool shotgun bore by means of which control is exerted to allow withdrawal of the cocking piece and upon the shot charge in order to throw its pellets thus cock the firearm in case of misfire, without into a definite area of predetermined concentration. the necessity of unlocking the bolt with the accompanying danger of the misfire being due to Degree of choke is measured by the approximate hangfire or delayed-action, which would create a percentage of pellets in a shot charge which hit dangerous situation. within a 30 inch circle at 40 yards. The follow- ing table gives the accepted percentages obtained COMB: Top of the butt stock or part of the stock with various chokes: which extends from the heel to a point just back Full Choke.................65-75% of the hand as the stock is grasped. It is the part Improved Modified...... 55-65% of the stock on which the cheek rests at the time of firing. A proper comb guides the face to such a Modified....................45-55% position that the eye falls quickly into the line of aim. Improved Cylinder..........35-45% COMB OF STOCK: The upper edge of the butt Cylinder Bore.............25-35% stock. The forward, highest point is called the point of the comb. SKEET PATTERNS: Winchester Skeet Choke gives a 95% pattern in a 38" circle at 20 yds.and COMPRESSION-FORMED: A process of a 95% pattern in a 48" circle at 25 yds. forming an all plastic one-piece shot shell case from a "slug" of plastic. Does away with paper CHRONOGRAPH: The instrument used to base wad and overlay wad. Strongest possible determine the velocity of a projectile in flight. construction. CLIP: A device for holding cartridges CONE: The slope of the forward end of the together, usually to facilitate loading. Erroneous- chamber of a shotgun which decreases the cham- ly used as a synonym for "magazine". A maga- ber diameter to bore diameter. Also called forcing zine has a feeding spring, a clip does not. cone. Glossary 7 CORDITE: Type of powder used by the Eng- different types of the same metal produced by lish to designate smokeless. A nitro-glycerine welding or twisting together dissimilar strips. base powder, actually a form of dynamite and Withstood pressures of old black powder loads, extremely hard on the bore of a rifle. It is still a but no smokeless powder loads of any kind are popular propellant in England, especially for big- to be used in guns having Damascus or twist bore rifles used in Africa. steel barrels. Avoid them. CRANE: The swinging unit that hinges the DELAYED BLOWBACK: A variant of the cylinder of a revolver with the frame. blowback principle in which the blowback operation is by some means retarded (e.g. by CRIMP: In rifle or revolver cartridges, the slight fluted or grooved chamber). bending in of the mouth of the case so that it grips the bullet, thus securing the bullet in the DIES: A term which can apply to numerous case. or several items in reference to guns, the most important of which are thread-cutting dies; CROSSBOLT: Transverse bolt used to lock cartridge-reloading and sizing dies; and dies the standing breech and barrels of a shotgun for the production of various types of parts together. commonly known as stamps, which are found so CROSSHAIR: Type of reticule consisting of often in modern firearms. fine crossed wires or hairs to designate the center of the optical field in a telescope sight. DISCONNECTOR: A device in auto pistols that prevents the pistol from being fired until the CUP WAD: A patented development first in breech is completely shut and prevents the pistol troduced by Western, which, coupled with from being fired fully automatic. exclusive base wad (see base wad), DOUBLE-ACTION: A type of lock work in actually "seals in" all powder gases and forms a either a revolver or auto pistol which permits the sealed gas chamber. Cup wad is just in front of hammer to be cocked either by direct manual powder. action or by a long pull on the trigger. CUT OFF: Part found in some rifle actions DRAM EQUIVALENT: A unit of measure: 16 which can be arranged to temporarily prevent drams (av.) in one ounce, or 256 in a pound. In cartridges from feeding from the magazine into the early days of black powder shot shells, the the chamber when the bolt or mechanism is powder charge was measured in drams. Drum [or operated. dram, today's smokeless powder is more power- ful. The term "3 dram equivalent" means that the CYLINDER: Usually applied to the part of the amount of smokeless powder used produces the revolver which contains the cartridge chambers same shot velocity as would 3 drams of black and which revolves so that each cartridge lines powder. up in turn with the barrel. It is used also in DRIFT: The deviation of the projectile from the connection with the description of a rifle barrel plane of departure due to rotation. In all sport- and applies to that part of the barrel which ing firearms it is so slight as to be of no conse- extends just forward of the receiver. quence. DAMASCUS BARRELS: A type of DRIFT OUT: Using a punch or similar tool to ornamental metal used in the manufacture of shot- drive out pins. gun barrels. Damascus applies to a combination of metals or different types of the DRIVING BANDS: Portions of a lead bullet's same metal produced by welding or twisting bearing surface that contact the bore. Driving bands together dissimilar strips. Also called "laminated." are separated by crimping and lubricating grooves. Damascus applies to a combination of metals or 8 Glossary DROP: The distance from the line of sight to ENERGY: The measure of the work per the top of the heel or point of comb of the stock formed by a bullet, expressed in foot pounds. or forearm. Often drop is specified from the line Energy does not always indicate killing power. of sight and also from the axis to the bore, since For example, a full-jacketed and soft-point the gunmaker is often called upon to build a rifle bullet may be given the same energy, but the complete with stocks, but without sights. former penetrates all the way through the game, expending but a fraction of its energy therein, DROP AT COMB: The vertical distance be- while the latter expends all its energy therein. tween the prolonged line of sight and the point Energy depends upon the weight of the bullet of the comb. The drop and thickness of the comb are the most important dimensions in the stock and the square of the velocity, hence it is less at of a shotgun or rifle. They are affected by and long range than at the muzzle dependent on the drop at heel. If the dimensions because the velocity has fallen off at long range. are correct the eye is guided into and held steadi- Energy is easily calculated. Simply multiply ly in the line of aim. The best standard drop at the velocity by itself, then by the weight of the comb for both rifles and shotguns is 1 1/2 to 1 bullet, and divide 450240 into the result. 5/8 inches. Thus 2220 x 2220 x 170 divided by 450240 DROP AT HEEL: The vertical distance = 1860 ft. lbs., the muzzle energy of the 30-30 between the prolonged line of sight and the heel Winchester cartridge. of the butt plate. The amount of drop varies, EROSION: The cutting or scouring out of the depending upon the ideas and physical steel in the barrel at the throat of the chamber conformity of the shooter. Most shotgun shooters by the hot gases escaping around the bullet. require a drop of about 2 1/2 inches, usually less The gases in a high power rifle cartridge are hot in a gun for trapshooting. enough to melt steel. ESCUTCHEON: Reinforcement border or EJECTOR: In general, the mechanism which bushing through which a screw or screws, or ejects or throws the empty case or loaded other fastening device, passes. cartridges free from the gun after it has been withdrawn, or partly withdrawn, from EXPRESS: Term usually applied to denote a rifle or cartridge of higher than usual velocities. the chamber by the extractor. Ejectors are commonly of two types, selective and automatic. EXTRACTOR: Part, usually shaped in the Specifically, in a break action shotgun, ejector form of a hook and attached to the bolt or actually includes the extractor. In double barrels, breechblock or other part of a rifle or chamber of selective ejection means automatic ejection of a firearm. It is the part which actually extracts or withdraws the fired case from the chamber, the the fired shell only. case later being expelled by the ejector. EJECTOR HAMMERS: In a break action FIRING PIN: The pointed nose of the hammer shotgun the driving pistons which eject the fired shells, utilizing the extractor(s. of a firearm, or the separate pin or plunger which, actuated by the hammer, or the mainspring, dents ELEVATION: The raise or elevation given to or the primer, firing the cartridge. required on the rear sight of a rifle to cause the FLASH (OR CYLINDER) GAP: The bullet to strike the target at a given distance. distance between the face of a revolver's cylinder ELEVATION, ANGLE OF: The angle between and the breech end of the barrel. U.S. industry the line of sight and the prolongation of the axis standards call for a gap of.006 inch, with a.003 of the bore which it is necessary to apply in inch tolerance. order that the bullet shall strike the target at a given range. Glossary 9 FLINTLOCK: A muzzle-loading gun fired by GAS-OPERATED: A system of operating an means of a piece of flint, held in the hammer or automatic or semi-automatic firearm in which "cock" jaws, striking against a steel "frizzen". a portion of the powder gasses is bled off from Incandescent particles of steel scraped from the the barrel and used to activate a piston or similar frizzen fall into a "pan" holding powder. This device that cycles the breech-block, bolt, or ignited powder flames through the "touch-hole" slide. thus firing the main charge. GAS CUTTING: The effect of the rushing FLOATING FIRING PIN: On a revolver, a of powder gases past a bullet in the bore, firing pin that is mounted inside the frame, as usually because the bullet is not large enough opposed to being pinned to the hammer. to completely seal the bore. Hot powder gases at high pressure when forced through a small FLUTE: Groove in various types of tools such orifice have considerable cutting or erosive as reamers, drills and taps. effect on the sides, both of the bore and of the FLUX: Substance or mixture of substances bullet. This defect sometimes occurs when rifles or chemicals used to facilitate the bonding of and ammunition are not accurately made, one metals together by means of soluble brazing or for the other. Also seen at the area above the welding. Fluxes are commonly made in the form cylinder, on the top strap of revolvers. of powder, pastes and liquids. GAUGE (gage): Term used for the FORCING CONE: The portion at the breech designation of shotgun bore sizes. Standard shot- of a revolver's barrel that tapers into the rifling, gun bores, ranging from the smallest to the larg- and the area forward of a shotgun's chamber est, are: 28, 20, 16, 12, and 10. Old guns were where the shot is "forced" into the barrel. often made in 8-gauge. They are no longer being produced in the United States..410 is usually FOREARM: Portion of the stock which is referred to as a gauge, but this is really a caliber, forward of the receiver and directly under the being the actual measurement of the bore. barrel of a firearm. It is sometimes called the fore-end, especially with respect to shotguns GAUGE, SHOTGUN: The unit of measure wherein the stock is made up of two pieces. of the bore diameter of a shotgun. The gauge is While it is a separate piece in the case of a two- the number of lead balls, of the diameter of the piece stock, it is simply the forward part of a gun bore, that make a pound. Thus, a 12 gauge, one-piece stock. or 12 bore means that 12 pure lead balls of such a diameter will weigh one pound. The standard FORE-END: The forward portion of a stock diameters of shotgun bores of various gauges are under the barrel which serves as the foregrip. as follows: FORGING: One method of working or shaping 4 gauge.......................935" metals. 8 gauge.......................835" FPS: Stands for "Feet per Second," by which 10 gauge......................775" bullet velocity is measured. 12 gauge......................730" FRAME: The skeleton or framework of a fire 16 gauge......................670" arm to which the barrel and stock are fastened 20 gauge......................615" and in which the breech, lock, and reloading mechanism are located. Also termed receiver. 28 gauge......................550" GALLERY: A term usually applied to an indoor 410 bore (36 gauge)....410" rifle or revolver range. 10 Glossary GRIP: Small part of the stock which is grasped manually every time the firearm is fired. The by the hand. It is also used to designate the word hammerless applies to a gun where the handle of a pistol or revolver. hammers are enclosed or concealed inside the action. GRIP, PISTOL: A portion of a stock which swells out, downward and to the rear in a form HAMMERLESS: Firearms having no visible approximating the handle of a pistol, or an actual vertical grip for use by the shooter's trigger hand. hammers. GRIP SAFETY: A device that prevents a HAND: Lever or dog which turns the cylinder handgun from being fired unless it is firmly of a revolver. The hand is attached to the trigger squeezed. or hammer and when the hammer is pulled back to cocked position, the hand is actuated and turns GRIP, STRAIGHT: A portion of a stock which the cylinder into position so the cylinder lock has approximately the same diameter and shape can lock the cylinder prior to the next shot. from front to rear for the shooter's trigger hand. HANG-FIRE: Term used to describe a delayed GROOVES: Spiral cuts in a bore which cause the bullet to spin as it travels down the barrel. action or delayed ignition when the trigger is pulled, the firing mechanism strikes the primer GROOVE DIAMETER: In rifled arms, the of a cartridge, but nothing happens until an diametrical measurement between bottoms of grooves. instant later. It can result in a disaster or a blown- up gun if the shooter does not wait long enough GROUP: A number of consecutive shots fired at to determine whether it is actually a misfire or a a target with constant aim and sight adjustment, hang-fire. In the event it is a hang-fire, and the their bullet holes making a group of shots on the target. The size of the group indicates the accu- bolt or locking mechanism is opened too soon, racy with which the rifle or pistol and its ammu the cartridge can explode when it is moved partly nition were shot, including the personal errors of or completely out of the chamber, but still in the the shooters. action of the gun. GROUP MEASURE: The distance in a straight HEADSPACE: For rimmed cartridges, the line between the two shots farthest apart in a distance from the face of the breech block to group of shots on a target. This measurement is the barrel seat for the forward surface of the made from center to center of bullet holes. case rim. For a rimless bottleneck cartridge, the distance from the face of the breech block GUARD: Term applies to the loop, usually to a predetermined point on the shoulder of the chamber. For rimless straight cartridges, the made of metal, plastic or horn, curving around distance from the face of the breech block to the trigger to protect it. It is commonly called the the shoulder or ledge in the chamber. Belted trigger-guard. cases headspace on the forward edge of the belt. When head space is too little the breech will not HAMMER: Part of the gun or rifle action that close on the cartridge. When there is too much, strikes the firing pin to fire the cartridge within misfires begin to occur, and the safety factor is the chamber. Guns are sometimes referred to lowered. Excessive headspace is dangerous and as hammerless, but all guns have some type may result in serious injury. of hammer or corresponding parts such as the cocking piece. The word "hammer" as applied HIGH BASE SHELL: An outmoded term for to hammer guns refers to outside hammers a shell furnished with high inside base wad, which can be cocked by hand. In some hammer approximately 3/4" thick before forming. Not guns, the hammer is cocked when the lever needed in the compression-formed Super-X and or slide is operated. Others must be cocked Super-Speed all-plastic shot shells. Glossary 11 HIGH BRASS SHELL: The highest LEADING: Deposits of lead left in the bore of quality of shotgun shells in which the brass base a rifle or shotgun. extends a considerable distance up on the plastic or paper tube. LENGTH OF STOCK: The distance in a straight line from the center of the trigger to HIGH POWER: A dated term used to designate a point midway between the heel and toe of the a rifle or cartridge having a muzzle velocity in butt plate, on the surface of the plate. Required excess of 2,000 feet per second. stock length depends upon the physical conformation of the shooter, people of short HINGE: The joint in a break action, breech stature or short arms requiring shorter stocks. loading rifle or shotgun connecting barrel or bar- Also called Length of Pull. rels with the frame. LINE OF SIGHT: The straight line passing HINGE PIN: Pin upon which the barrel or from the eye through the sights to the target. barrels of break actions hinge. Also termed the line of aim. IMPROVED CARTRIDGE: Form of a LOCK: The combination of hammer, firing wildcat cartridge usually made by fire-forming pin, sear, mainspring and trigger which serves the cartridge. A factory cartridge can be fired in to discharge the cartridge when the trigger is a slightly altered chamber, thus blowing the case pulled. It is also known as the fire control or out to create a wildcat or improved cartridge. trigger group. This means a rifle chambered for one of these cartridges will still handle factory ammunition. LOCKING BOLT: The bolt used in a break down, breech-loading gun to lock the breech INERTIAL FIRING PIN: A firing pin that is too short to contact the cartridge's primer in its closed position. Also in certain repeating when the hammer is resting on it and can only rifles, the sliding blocks which lock the breech in hit the primer when driven forward under the its closed position. momentum of the hammer blow. LOCKSPEED (LOCKTIME: The time JHP: Stands for Jacketed Hollow Point; a bullet consumed between the releasing of the firing similar to a Jacketed Soft Point, except that a mechanism and the explosion of the cartridge. portion of the nose is hollowed out for greater bullet expansion. LUBRICATION OF BULLETS: Most lead bullets have to be lubricated with a grease JSP: Stands for Jacketed Soft Point, a type of or wax placed on their surface or in their bullet with a soft lead core enclosed by a hard grooves to prevent leading the bore. Externally metal jacket, but with the nose section exposed lubricated cartridges have the lubricant placed to allow bullet expansion. on the surface of the bullet outside the case. KNURLING: The checkering of metal to Internally lubricated bullets have the lubricant produce a rough surface. placed in grooves or cannelures on the bullet and it is concealed by the neck of the case. LANDS: Term used to describe the space between the grooves of a rifle barrel. It also LUG: In a breakaction, breech-loading shot gun describes the space or ridges between the flutes or rifle a lug on the barrel which secures the on reamers and other tools which have flutes. barrel to the frame. Lugs located on the front of a bolt or breech block rotate into slots to lock the LAP: Piece of soft metal in the form of a plug or action for firing are termed locking lugs. other shape which can be charged with abrasives. MAGAZINE: The part of a repeating firearm LARGE BORE: In the United States, any rifle which receives the cartridges, from which they of.25 caliber or over is termed a large bore, or big bore. are fed into the chamber when the repeating 12 Glossary mechanism is operated. There are numerous MONTE CARLO: Form of stock in which the types of magazines such as box, tubular, rotary, comb extends horizontally or parallel to the axis etc. of the bore to within a short distance of the heel, where it descends abruptly to the heel portion. MAGAZINE, BOX: One in which the On rifles, Monte Carlo stock is popular with cartridges are horizontally stacked. target shooters for it helps them use target-type sights which are mounted necessarily rather high MAGAZINE Follower: A spring-actuated above the bore. It is also quite popular among plate which feeds the cartridges or shells in a shotgun trap-shooters. magazine into loading position. MOUNTS: Metal bases used to secure a MAGAZINE, FULL: A tubular magazine telescopic sight to the barrel or receiver of a reaching the full length of the barrel. firearm. MAGAZINE, HALF: A tubular magazine MUZZLE: End of barrel opposite to breech; reaching half the length of the barrel. point from which bullet or shot leaves barrel. MAGAZINE, TUBULAR: One in which the NIPPLE: Tube which receives the percussion cartridges are carried end-to-end in 11 tube cap of a muzzle-loading or percussion-loading located either beneath the barrel or within the firearm. It is a small projection through which stock. there is an opening leading to the powder charge MAGNUM: In connection with firearms it in the barrel. Upon detonation, the flash from the serves to designate rifles using extremely large, cap is carried through the opening in the nipple, powerful cartridges. It is also used to describe a into the powder charge in the barrel. firearm of greater-than-average power. O'CLOCK: A term used by riflemen to MAINSPRING: The spring, either flat or coiled, indicate a location on the target or on the rifle which provides the energy to carry the hammer range, corresponding to similar locations on the or firing pin forward to strike the primer. face of a clock; 12 o'clock being at the top of the target, or at the target end of the rifle range. MATCH RIFLE: A rifle explicitly designed for Thus a shot striking the target immediately to competitive shooting, normally on an organized the left of the bull'seye is a hit at 9 o'clock, and basis. a wind blowing from the right at a right angle to MATTED RIB: A raised, solid rib along the the line of fire is a 3 o'clock wind. top length of a shotgun barrel to cut reflection and improve sighting. See RIB. OLIN BALL POWDER: The big advantages of Olin Ball Powder are: no excessive smoke M.C. METAL CASE: Form of bullet or muzzle flashing, clean burning, excellent completely covered forward with copper or stability in all climatic conditions, less gun barrel copper alloy (usually) jacket. Generally a wear due to erosion, and positive lots and speed military bullet type, and also termed "solids", duplications. The process of manufacturing and F.M.J. (full metal jacketed). smokeless ball powder is one that has been MEAN RADIUS: The scientific method of completely developed at East Alton, Illinois by measuring a group of shots fired on a target Olin Mathieson. Years of extensive research from a rifle or pistol. It is the average deviation of special trained chemists and chemical from the centerpoint, found by adding the engineers were required to perfect the process. measurements and dividing the result by the All smokeless powders prior to the Olin Ball number of shots. were manufactured by a method known as the extruded powder process. It required large METAL FOULING: A deposit of bullet-jacket bulky equipment-hydraulic presses and mixers. metal left in the bore of a rifle. Glossary 13 Ball powder is prepared in large agitated vats PISTOL: Said by some to derive from Pistoia, equipped with condensers. The extruded process an early gun making center in Italy. Any small, requires from six weeks to six months before concealable, short-barreled (2"–10") hand the powder is ready for use. In the process, the weapon. A hand gun in which the cartridge is materials are handled seven or eight times. A loaded into a chamber which is in the barrel. complete lot of Olin Ball Powder can be made When the cartridges are loaded in and fired from a revolving cylinder, the pistol is termed a from basic raw materials in 60 hours. It is revolver. handled only one time and this is after drying process has been completed. PISTOL GRIP: Part of the gun stock which turns down just to the rear of the trigger, forming OVER AND UNDER: Double barrel shotgun a handle similar to that used on a pistol or or rifle with one barrel superimposed over the revolver. Stocks are made either with a pistol other. grip or a straight grip. PATCHED BULLET: Many bullets used in old PITCH: Term used to describe the angle of the black-powder rifles were patched or surrounded butt of the firearm in relation to the bore or line with an envelope of paper. In muzzle loading of sight. It is also used to describe the distance days, wrapping the bullet in a small greased from the center of one screw thread or gear linen patch was a common practice. That tooth to the center of the next. If a screw has explains the origin of the term. ten threads to the inch, it is said to have a thread pitch of ten. PATTERN: The distribution of a charge of shot PITCH OF BUTT: The angle of the butt or fired from a shotgun. See CHOKE. butt plate with relation to the gun's barrel. If PARABELLUM: Means "prepare for war". on resting the butt of a gun on a smooth floor, From Latin "si vis pacem, para bellum." "If you barrel vertical, the barrel inclines at the muzzle towards its under surface so that the muzzle is want peace, prepare for war." The European two inches from a perpendicular line through designation of the 9mm cartridge. the breech, the butt is said to have a pitch of two inches. If the barrel inclines in opposite PEENING: The process of hammering a metal directions, it has a negative pitch. If the barrel is piece to indent and compress it thus expanding , truly perpendicular there is no pitch. A pitch of stretching, or reforming it. A ball peen hammer is 2 or 3 inches is desirable on a repeating rifle as it used by gunsmiths for this operation. causes the butt to remain in place at the shoulder when the mechanism is operated in rapid fire. PENETRATION: The distance a projectile travels within a given material. PLINKING: Shooting a weapon of any type for the sheer fun of it under safe conditions. PERCUSSlON: Striking and crushing, the POLYFORMED: A process of forming a method by which certain explosives used continuous plastic tubing for shot shell cases, in priming mixtures are ignited. In modern which is then cut into requisite lengths. ammunition the priming mixture within the Polyformed plastic shells are made with the centerfire primer, or the folded rim of a rim conventional paper base wad and fire cartridge is crushed by the indenting of the overlay. Plastic Ranger and Xpert shells are primer cup or rim by the firing pin. The cap polyformed. used on the nipple of muzzle-loading guns and PORTING: May mean either lowering the crushed between the nose of the hammer and the ejection port of a self-loading pistol to ensure nipple was called a percussion cap. greater reliability and less damage to cases, or the practice of adding gas vents in a barrel to reduce muzzle jump. 14 Glossary POWDER: The finely divided chemical RAMP SIGHT: An incline. A front sight of mixture that supplies the power used in shot a large type which is a long slanting piece of gun and metallic ammunition, technically metal, attached to the muzzle-end of a barrel propellent powder. When the powder is ignited and provided with a means for holding the front by the flash of the priming composition it burns sight. Actually, it is a base for the front sight. with a rapidly increasing gas which develops RANGE: The distance measured from the firing point of the firearm to the target. Also a place a pressure of from 6,000 to 55,000 pounds where rifle and pistol shooting is conducted. per square inch in the shell, chamber and bore of the gun. This gas furnishes the propelling RANGE, EXTREME: The greatest distance force of the bullet or charge of shot. Originally, to which a bullet of a given cartridge fired from all propellent powder was black powder, a rifle will travel before the bullet cuts the same which was fanned in grains of varying size, horizontal plane from which it departed. With the size of the grain determining the rate of small arms extreme range is always obtained by burning and suitability for various cartridges. elevating the barrel at an angle of 45° from the Modern powders are smokeless and their base is either nitroglycerine or nitrocellulose, or a horizontal. combination of both, in which case it is said REAMER: Tool used to enlarge an already to be double-base powder. The rate of burning existing hole. For example, a hole is drilled and is controlled both by the composition, by the then reamed to exact size. size and shape of the grains and whether or not coated with some retarding substance called a RECEIVER: The frame consisting of breech, deterrent. Those so coated are called progressive locking and reloading mechanisms of shotgun burning. or rifle. POWDER, PROGRESSIVE DURNING: A RECOIL: The backward thrust of a gun caused propellent powder while is relatively slower by the reaction to the powder gases pushing the than other powders in developing its pressure. bullet forward. In these shells the crimp is opened up and the shot charge started on its way before a complete RECOIL OPERATED: A form of locked- pressure is reached. This results in less jamming breech semi-automatic operation in which the and deformation of the shot, reduced recoil and barrel and breech remain locked together during improved pattern at long range. the peak pressure, then move rearward under recoil to effect unlocking and reloading. PROJECTILE: A ball, shot, or bullet fired from a firearm. RECOIL PAD: A soft pad which replaces the PRIMER: In a centerfire cartridge, the small usual butt plate on a shotgun or a high power cup containing a detonating mixture, which is rifle. Used to ease or soften the recoil on a seated in a recess in the base of the case. When shooter's shoulder. the primer is indented by the firing pin, the priming composition is crushed, and detonates, RECOIL SHIELD: The enlarged portion thus igniting the charge of powder. Rim fire of a revolver's frame immediately behind the cartridges contain the priming composition cylinder. within the folded rim of the case, where it is crushed in the same manner. REVOLVER: Type of repeating firearm which has a revolving cylinder containing chambers for PUMP ACTION: Common name for a slide the cartridges. action repeating firearm. REGISTERED TARGETS: Shotgun target RAMP, BARREL OR FEED: An inclined thrown in a tournament registered by the area of the barrel mouth or frame which guides Amateur Trapshooters' Association, the Na the cartridge into the chamber. tional Skeet Shooting Association, or National Sporting Clays Association. Glossary 15 REGISTERED TOURNAMENTS: Are contained inside the rim of the case or shell and conducted through registration with the not in a separate primer. N.R.A. which appoints official referee to be in attendance; only official N.R.A. targets can be SAFETY: The mechanism which mechanically used so that exact dimensions are guaranteed for locks a firearm, preventing the possibility of all participants. accidental discharge. In common practice the term applies primarily to the button, pin or REPEATING FIREARM: Any rifle, shotgun toggle which, when set in the "safe" position, or pistol, other than a revolver, having a mag prevents the discharge of the arm by pulling azine in which a reserve supply of cartridges is the trigger. No safety is "foolproof," as they are carried, and a repeating mechanism which, when mechanical and thus subject to failure! operated, ejects the fired cartridge case and re- places it with a loaded cartridge, ready to fire. SAFETY, AUTOMATIC: A safety device which automatically resets itself in the "safe" position when the gun is opened during the REVOLVER: A pistol in which the cartridges reloading process. are placed in firing position by a revolving cyl- inder. SAFETY, NON-AUTOMATIC: One requiring hand-setting for the "safe" position. RIB: The raised bar, sometimes slightly concave on its upper surface, and usually matted, which SCHNABEL: Forward tip of the forearm, forms the sighting plane extending from breech usually taking some form such as a knob or to muzzle of a shotgun. enlarged section. RIFLE: A firearm with the bore of its barrel cut SCHUETZEN RIFLE: Late 19th and early or rifled with spiral grooves. the object of which 20th century style of heavy target rifle in- is to cause the projectile to rotate on its axis tended primarily for offhand shooting, usually when fired, thus increasing its range, stability, distinguished by a heavy buttstock with large and accuracy. cheek piece, a much curved butt plate with long underprong, a heavy barrel, and target sights. RIFLED FORSTER/FOSTER SLUG: A Much used for target shooting in Europe, and special shot shell with a single bullet-shaped by GermanAmerican rifle shooters; once high in projectile with hollow base and scientifically popularity in this country, the rifle is regaining rifled sides. Accurate up to 100 yards. Designed limited use in International type of shooting. for use on big game in those areas where rifles are prohibited. Will not harm shotgun barrels and SEAR: Part of a firing mechanism which will not "ream out" any type of choke. engages the hammer or cocking piece. When RIFLING: The spiral grooves cut in the bore the trigger is pulled, it releases the sear, which of a rifle or pistol barrel. The object of these in turn releases the hammer or firing pin. The grooves is to rotate the elongated projectile so sear is usually an integral part of the trigger, but that it will fly point-on to the target. A rotating sometimes it is a separate part within the fire- projectile has a gyroscopic stability which control group. causes it to resist any force tending to deflect it SELF-LOADING: A type of firearm which, by from the direction it takes as it departs from the pulling the trigger, utilizes the energy of recoil, muzzle of the rifle. or the powder gases, together with a heavy The longer the bullet and the lower the velocity, counter-balanced bolt and strong bolt spring, to the quicker the twist must be to cause the bullet eject the fired case, load a fresh cartridge from to travel with point to the front. magazine into chamber, and dose the breech RIM FIRE CARTRIDGE: A metallic ready to fire another round. The trigger must he cartridge in which the priming composition is pulled for each shot. Also termed autoloading 16 Glossary or semiautomatic. Should be distinguished from SKEET: A variety of shotgun shooting at clay automatic in that it requires manual operation targets thrown from traps along fixed lines of the trigger for each shot while an automatic, of flight; a game designed to simulate field shooting conditions. technically, is one which fires repeatedly and rapidly as long as the trigger is held back and SKEET GUN: Shotguns with barrels bored to cartridges remain in the magazine. Erroneously, shoot an open pattern, suitable for skeet shooting. the term "automatic" is commonly used to describe selfloading small arms. SLIDE ACTION: See Pump Gun. SEMI-WADCUTTER (SWC): A bullet with SMALL ARMS: A military term referring to a flat-ended nose section and full caliber butting firearms no larger than 45 caliber-used by the shelf. individual. SET-TRIGGER: Trigger mechanism designed SMALL BORE: There is no universally recog for lightening the trigger pull. There are many nized measurement indicating whether a firearm is types of set-trigger mechanisms, both double a small or a large bore. American shooters usually and single. With a double-set style, one trigger consider any shotgun under 20 gauge and any rifle is pulled or pushed to "set", the other trigger under 25 caliber as being small bore. 22 rim fire can then be released by the slightest touch. rifles have come to be termed "small bore" rifles. With single-set trigger mechanisms, the normal procedure is to move the trigger itself ahead until SMOOTH BORE: A firearm without rifling. it catches in the forward position, at which time only the slightest pressure is required to set it off. SPOTTING SCOPE: A telescope used on rifle Set-triggers of various types are popular among ranges, by marksmen and onlookers, to see the target shooters, but they are not used extensively bullet holes-or the markers placed over them. for hunting purposes. SPREAD: The overall area of a shotgun SHELL: A loaded shotgun cartridge. Also, shell or case means the empty case of any cartridge. pattern, of its shot, taken at right angles to its line of flight. SHELL, PRIMED OR PRIMED CASE: An empty casing containing a live primer. STANDING BREECH: The face of the frame of a double barrel shotgun which closes the SHOT: Lead or lead-alloy spheres used as barrels at the breech. projectiles in smooth-bore guns. STOCK: The wooden or polymer part of a SHOTGUN: A smooth-bore firearm which shotgun or rifle, or the sides of the handle of a shoots a large number of small shot or a single pistol or revolver. large projectile. See Rifled Slug. STOCK, BUTT: The butt section of a firearm SIDE BY SIDE: A double barrel shotgun with in which the forearm is separate from the butt the barrels alongside of each other. stock. SIGHT RADIUS: The distance between the front and rear sights. The longer this distance. STOCK, ONE-PIECE: The stock of a rifle in which the butt stock and fore-end are all in one the greater the accuracy attainable. piece. SILVERTIP: A bullet development by (STRING) SHOT: The lengthwise area of a shot Winchester-Western which provides controlled expansion upon impact and deep penetration, charge, or distance from front to back as it passes with a definite check on excessive upsetting through the air. which would cause the bullet to break and lose effectiveness. TAKE-DOWN GUN OR RIFLE: A firearm in which the barrel and adjacent parts can be Glossary 17 readily separated from the receiver or action, TRIGGER: The small lever under the fire- thus permitting the arm to be packed in a short control mechanism of a firearm. When it is container. pulled to the rear it releases the hammer or firing pin, discharging the cartridge in the chamber. TANG: Extension of an action used to attach the metal parts to the stock. Some types of actions TRIGGER GUARD: A guard surrounding the have long tangs extending well down both top trigger or triggers of a firearm to protect the and bottom of the grip. Tang sights are sights trigger from damage or accidentally discharging which are designed to attach to the upper tang of the weapon. a rifle. TRIGGER PULL: The weight or power TARGETS: Targets are of two kinds: paper required to pull the trigger of a firearm, measured targets for rifle and pistol shooting, and the so- called "clay birds" used in trap, skeet and hand- in pounds. trap shooting.

Modern Gun School Unit 1 - Advanced Gunsmithing Program PDF

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