If you think you can get by cheaply by not investing the time in training an armorer, the consequences may be more than you are prepared to deal with. For those commanders and leaders who may read this, I hope you have a greater appreciation of the importance of this duty position.
If you have no local training resource to conduct armorer or firearms training, do not hesitate to contact me. I am always willing to travel, local schedule permitting, to other installations and locations to conduct training. The only cost involved is the TDY travel expense.
Good luck, and good shooting!
Armorer’s Glossary
Marksmanship Term Definition
Accuracy Accuracy is the ability of a firearm and its ammunition to fire bullets into small groups at various ranges. For sporting purposes, a rifle is considered accurate if it will shoot into a circle, the diameter of which does not exceed 3 minutes of angle at 100 yards.
Accurize To modify, rework, and refine a weapon in order to improve the characteristics of the designed function and accuracy capabilities.
Action The part to which the barrel is attached. In a rifle it is often called the receiver. Shotgun or double-barreled sections house all the mechanism or working parts. The term may be further modified as side-action, breech-action, belt-action, snap-section, etc. It is also used to indicate the different forms of charging the weapon such as bolt-action, lever-action, pump-action, etc.
Adapter An auxiliary chamber to fire smaller cartridges in a barrel of like caliber, but having a larger chamber.
Adapters are made to conform to the outer walls of the chamber and reamed to fit the auxiliary cartridge.
AFQC Air Force Qualification Course: Course of fire fired
by Air Force personnel with a weapon, to determine their individual proficiency under the provisions of Air Force Instructions (formerly called Air Force Regulations).
Aggregate The sum total of the scores from two or more matches.
This may be an aggregate of match stages, team matches, individual matches or both, provided the tournament program clearly states the matches which will compromise the aggregate.
Aim To point or direct a weapon that propels a projectile
towards an object or spot with intent to hit it.
Air Gauge A mechanical device operated by air pressure used to
Air Gun A weapon which uses air to propel the projectile.
Air Resistance See Ballistic Coefficient.
Alibi A slang term used in competition to define an allowable refire.
Alignment See Sight Alignment.
Alloy A metal composed of two (2) or more metals and/or other ingredients mixed together while molten.
Alternate An extra member of a competitive team, whose utilization is prescribed by match conditions.
Ammunition Type of munition normally containing an explosive element and designed to inflict damage upon
structures, personnel, materiel, or military objectives.
Ammunition includes shells, grenades, pyrotechnics, bombs, and mines, together with projectiles such as bullets, shot and their necessary primers, fuzes, propellants and detonators. See Small Arms.
Angle of Departure The angle of departure is actually the angle of elevation for the given range. Also describes the degree of deviation from a plotted course or trajectory.
Anneal To render soft, as in the case of metals by heating to a low red heat, and allowing to cool.
Anodize To subject a metal to electrolytic action as the anode of a cell in order to coat it with a protective film or color.
Anschutz German manufacturer that produces standard and free rifles. Also a common name for a type of stock.
Anvil A component part of primer construction against which an explosive primer mixture is smashed in order to initiate combustion. See Boxer Primer and Berdan Primer.
Arched Housing Referring to the mainspring housing of the .45 caliber automatic pistol, a housing with the rear portion curved where it contacts the palm of the hand.
Armory A place where firearms and instruments of war are deposited. Police armories are usually vaults with alarms and access controls. Military armories are usually a large building containing an arms vault, drill hall and offices. Also, a manufactory (usually one belonging to the government) of arms, such as rifles, pistols, machineguns and bayonets.
Armor-Piercing A projectile designed for use against armored aircraft and vehicles. Normally has a hardened steel alloy core.
Arms A term used to describe hand, shoulder, and light
automatic weapons.
Arsenal An establishment, not usually public, for the storage, repair, manufacture or issue of arms and military equipment whether for land or naval service.
Artificial Support A competition term describing any supporting surface not specifically authorized for a shooting position.
Assembly The act of building a weapon to a complete unit, from parts already manufactured. Also, a collection of parts so assembled as to form a portion of, or complete weapon.
Assembly Line The area to the rear of the firing line where competitors assemble prior to their relay being called to the ready line and the firing line.
Autoloading Arms in which the force of the explosion of each shot is used to unlock the mechanism, extract and eject the empty shell, and to reload by stripping and feeding another cartridge from the magazine and into the chamber. The trigger must be pressed for each
successive shot.
Automatic Arms in which the force of the explosion of the first shot is used to continue the operation of unlocking, extraction, ejection, reloading, locking and firing continuously, as long as the ammunition lasts in the magazine, belt or strip, and the pressure on the trigger is continued. This name is commonly applied (in error) to autoloading, repeating firearms, especially pistols.
Auxiliary Chamber Same as Adapter.
Average The overall performance rating of an individual in his ability to score with a particular type of weapon, determined after firing a definite number of rounds or matches. This number is usually figured on a percentile basis and is used in establishing a classification.
Award Prize given to winning shooters or teams.
Any Rifle An NRA term meaning a centerfire rifle of any caliber or weight, not equipped with a Schuetzen-type butt plate or palm rest, nor with a trigger capable of set
Aperture A front or rear sight, using a hole for viewing to obtain sight picture and alignment. Also the adjustable or changeable disks that are components of the front or rear sight to obtain different diameter holes for viewing.
Apex Extreme forward point of projectile.
Axis A straight line, real or imaginary, that passes through
a body and about which the body may, or actually does, revolve.
Backing Targets A blank target placed to the rear of the scoring targets, to assist in identifying the number of rounds fired, and crossfires, in precision shooting.
Backstop A mound of earth, a hill, or any other barrier, which will safely deflect, stop or absorb bullets.
Base Wad An integral part of shotshell construction, which separates the brass head from the powder charge. Its function is to seal the chamber, prevent sticking of fired shells, protect the shooter from blowback, and aid in obtaining uniform pressures and velocities.
Baffles Structures of wood or other materials, used on the firing range, to deflect and/or absorb stray or ricochet bullets.
Ball Ammunition Small arms cartridges with a general purpose, solid core bullet intended for use against personnel and material targets not otherwise requiring armor piercing or other special ammunition.
Ballistics The science that deals with the motion, behavior, appearance, or modification of missiles, propellants, rifling, wind, gravity, temperature or any other modifying substance, condition, or force. The art of designing missiles or projectiles so as to give them efficient motion and flight behavior with the limitations set up by their purpose. See also Interior Ballistics, Exterior Ballistics, and Terminal Ballistics.
Ballistic Coefficient A numerical value, designated as a decimal fractional equivalent between the numbers zero and one, which indicates the effect which air resistance will have upon the flight of a missile or projectile. The larger the ballistic coefficient, the more closely will the trajectory correspond to the ideal flight which would be obtained if the missile could be projected in a vacuum.
Ballistic Form Factor One of the factors used in a formula to determine a ballistic coefficient.
Ball Powder A propellant composed of small dense spheres of nitrocellulose coated with a layer of nitro-glycerine and a detergent.
Band, Barrel A ring, usually of metal, encircling the barrel, used for attaching forearms or other parts or accessories.
Bandoleer (or Bandolier) A belt-like cloth, or other material, with compartments designed for carrying ammunition, worn suspended over one shoulder, across the chest, or under the arm.
Barrel That part of a gun or firearm through which the projectile is fired and which gives direction to the projectile.
Barrel Blank A steel rod or tube that has been bored and rifled for a given caliber, but unchambered and unthreaded.
Barrel Whip Movement of the barrel during the process of firing.
These movements are transmitted to the barrel by the forces of the propelling gas and the kinetic energy developed by the projectile.
Battery Description of a weapon locked in firing position.
Battery Cup A primer housing used in shotshell reloading.
Battle Sights A predetermined sight setting that, carried on a weapon, will enable the firer to engage targets effectively at battle ranges when conditions do not permit exact setting of sights.
Bead A small knob of metal on a firearm near the muzzle,
used for a front sight in aiming.
Beaver Tail The forearm portion of a rifle or shotgun whose dimensions are wider than normal.
Bedding The precision fitting by hand of a rifle barrel, receiver and guard, to its stock, to increase and maintain its accuracy.
Belt Short for ammunition belt, usually linked.
Belted Cartridge A cartridge design of the rimless type, employing a step-cut or shoulder approximately one-eighth inch in front of the extractor groove. This shoulder gives the appearance of a metallic "belt" around the case. The belted case, therefore, enters a counterbored chamber and the "belt" around the head of the case strikes the shoulder or forward face of the counterbore, thus
Bench Rest A rigid bench for rest shooting of firearms.
Bench Rest Shooting (a) Shooting from a bench rest. (b) A type of sport or competition shooting, where an attempt is made to fire a number of shots into the smallest possible group; the ultimate aim being to have all shots of one group in one bullet hole. There are practically no restrictions as to weapon size, caliber, design, shape or weight. The goals of organized bench rest shooters are development and encouragement of extreme accuracy in rifles, ammunition, equipment and shooting methods.
Bend The drop below the line of sight at the comb and heel of
a buttstock.
Berdan Primer A center fire primer, popular in Europe and Asia, whose anvil is constructed out of part of the cartridge case. Not interchangeable with the Boxer Primer.
Biathlon An event combining cross-country ski racing and shooting.
Big Bore A slang term used to define the weapons used in NRA or National High Power Rifle Matches.
Binocular Vision Sighting with both eyes open.
Bipod A two-legged stand or mount for a scope or weapon.
Black Powder A mixture of finely divided charcoal, potassium nitrate and sulfur, used as a propellant or explosive.
Blacken Sights To apply any black substance to sights to eliminate
glare. The common method is to use a carbide lamp allowing flame to deposit carbon on the sights.
Blade Sight A metal blade, attached to the upper side of the barrel near the muzzle.
Blank Cartridge A cartridge having, in place of a projectile, a paper cup or wadding in the mouth of the case.
Blowback (a) Escape, to the rear and under pressure, of gases formed during the firing of the gun. Blowback may be caused by a defective breech mechanism, a ruptured cartridge case or a faulty primer. (b) Type of weapon operation in which the force of the expanding gases acting to the rear against the face of the bolt furnishes all the energy required to initiate the complete cycle of operation of the gun. A weapon which employs this method of operation is characterized by the absence of any breech lock or bolt lock mechanism.
Blown Primer A primer that has ruptured or unseated itself in the base of the cartridge. May be due to excessive pressure, defective primer, improper firing pin length, or the brass case being improperly annealed (soft brass).
Bluing An oxidizing process which is used to color metal in various shades of blue and tends to prevent rust.
Boat-tail The tapered rear end of a bullet designed to increase ballistic efficiency at long range, by reducing base drag.
Boil The appearance of an upward, boiling-like motion of
mirage, when not affected by wind shift.
Bolt A sliding mechanism that closes the breech in some
types of small arms. It usually contains the extractor and firing pin, and supports the base of the cartridge.
Bolt Action A firearm whose locking and unlocking action is controlled by the manual operation of the bolt.
Bolt Face That portion of the bolt that engages and supports the head (or base) of the cartridge.
Bolt Handle That portion of the bolt grasped for manual operation.
Bolt Head The forward section of a two-piece bolt.
Bolt Sleeve The steel machining at the rear of the bolt that serves to unite all the components of the bolt assembly.
Bone Support The position the firer assumes that allows him to use his bones to support the weight of the weapon and use his muscles principally to hold bones in their support-ing position. This means that he can keep his muscles relaxed and avoid the tremors that develop from strain and tension.
Bore (a) The interior of the barrel through which the charge or bullet passes. (b) The diameter measured from land to land.
Bore Reflector A device containing mirrors to inspect the bore.
Borescope A device used to examine the interior surfaces of the bore of a weapon. Usually a collection of lenses within a tube, with a reflecting mirror and light, capable of enlarging the view of the area being inspected. May also be a fiber-optic device, or a mount for a small remote camera which projects the image on a screen for the
Boresight An instrument inserted in the bore of a weapon to determine the bore axis and its alignment with the sights of the weapon.
Bottleneck A cartridge case whose neck diameter is smaller than its base.
Boulenge Test A method of determining bullet velocity by using a type of chronograph.
Boxer Primer A center fire primer favored in the United States. It is a completely self-contained unit whose anvil is a small metal cone inside the primer cup.
Brass Empty brass cartridge case.
Breath Control To exercise proper control of the breath during the aiming and firing process, in such a manner as to minimize disturbance of sight alignment and sight picture.
Breech The rear end of the barrel into which the cartridge is inserted.
Breech Block Any steel device used to seal the breech of a rifle at the instant of firing.
Browning (a) An oxidation produced and retained on the surface of gun barrels by means of acid, to stop further oxidation or rust. (b) Any weapon designed or manufactured by John M. Browning or the Browning Arms Company, such as the Browning Automatic Rifle.
Bridge Metal arch connecting both sides of a receiver.
Bull Gun An extra heavy barreled sporting or target rifle. The extra weight of the barrel reduces vibration, insuring greater accuracy.
Bullet The projectile fired from a small gun.
Bullet Base Rearmost end of the bullet.
Bullet Drop The vertical drop of a bullet due to gravity.
Bullet Gauge Gauges normally used to measure the diameter and concentricity of a bullet.
Bullet Profile Shape of bullet from nose to base.
Bullet Pull The energy required to pull a bullet from its case.
(The bullet pull is used as a measure of the uniformity and efficiency of the crimp holding the bullet in its case)
Bullet Puller Device used to remove a bullet from the cartridge case.
Bullet Trace The visible path of a bullet passing through the atmo-sphere which can best be seen through properly adjusted optical aids.
Bullseye (a) The center of a target; also a shot which hits it;
hence any successful hit. (b) The blackened area of a target. (c) A trade name for a commercially produced pistol powder.
Butt Plate A plate of metal, plastic or horn placed on the butt to protect the buttstock against damage.
Buttstock The portion of a stock from the action rearward.
Cam A rotating piece, eccentrically pivoted; placed in
different parts of weapon actions to give short locking motions.
Cam Effect Locking or moving with a cam.
Camming Slot An engagement surface, usually a diagonal recess, used in conjunction with a cam or roller assembly.
In firearms, it is often cut into the surface of a bolt, and used to cause rotation of the bolt for locking or unlocking.
Cannelure A groove in a bullet for containing a lubricant or into which the cartridge case is crimped; a groove in a cartridge case, providing a purchase for the extractor.
Cant To revolve to the right or left on the axis of the bore while aiming; as, to cant a rifle.
Caliber The diameter of a projectile, as of a bullet or shell;
the diameter of the bore of a gun barrel. In rifled arms, the caliber is measured from the surface of one land to the land directly opposite. In the US and Great Britain, the calibers of small arms and their ammunition are usually expressed in hundredths or thousands of an inch; when so expressed, the designation usually represents a close approximation rather than an exact measurement. In continental Europe, calibers are normally expressed in millimeters.
Call The ability of a shooter to determine the approximate
location of his hit on the target through noting the position of the sights at the instant of firing.
Carbide Lamp A miner's-type lamp whose flame is used to put carbon deposits on sighting equipment to reduce glare.
Carbine A light weight shoulder arm or rifle having a short barrel, originally used by cavalry.
Carrier Block That part of a weapon which lifts a round from the magazine and lines it up with the chamber. Usually found in pump and automatic shotguns and some types of rifles.
Cartridge A complete round of ammunition, containing bullet, powder, case and primer.
Cartridge Case Usually a brass or steel case used to house bullet, powder and primer.
Case Forming Resizing the cartridge case to a specified size and shape by the use of a resizing die.
Case Gauge An instrument used to measure the case length against a standard.
Case Hardening The process of hardening the surface of metal while leaving the core soft.
Case Trimming A method of shortening a cartridge case to a specific
Case Trimming A method of shortening a cartridge case to a specific