Ammunition, Technical, Gun-Related
Accurate Arms - modern gun powder manufacturer
ACP - automatic Colt pistol
AE - action express
Anneal - To soften metal by heating. Used to extend the useful reloading life of brass cartridge case necks by softening them and permitting more reloading operations to be performed before the work hardening effect of the cold, forced reshaping of the resizing operation causes metal fatigue in the neck area and makes the brass case unusable for further reloading. Brass and copper are annealed by fast cooling, usually by quenching, from a heated condition. Steel is annealed by a slow cooling. Quenching of steel from high heat has the opposite effect from the same treatment of brass and copper.
AP - armor piercing
API - armor piercing, incendiary
APT - armor piercing, tracer
AR - assault rifle
BAR - Browning Automatic Rifle
Bearing Surface - that portion of a bullet that contacts the bore of the barrel as it travels from chamber to muzzle. Sufficient bearing surface is required for good accuracy.
BBWC - Bevel Base Wadcutter (bullet design)
BC - ballistic coefficient: indexed measure of a bullets ability to overcome resistance in flight relative to the performance of a standard projectile used to compute ballistics tables. (mathematically: ratio of bullet's SD to its coefficient of form, or the ratio of bullet's weight to the product of the square of its diameter and its form factor (coefficient of form)).
Bedding - material and/or methods used to fit rifle action to a stock.
BMG - Browning machine gun
Bore - the inside of a firearm's barrel.
Bore sight - to align the sights of a firearm by sighting through the barrel bore
BP - black powder
BPCR - black powder cartridge rifle
Brisance (brissance) - the "shattering" effect of explosives; the burn rate, in terms of acceleration, i.e., how quickly is the maximum burn rate of an explosive mass reached?
BT - boattail (bullet design)
Bullet - the projectile which is expelled from a firearm's barrel at firing
Burn rate - the relative speed at which gun powders burn (explode) This is determined by the size and shape of granules, amount and nature of any coatings and, in some cases, specific physical design of the granules, such as perforations, tubes, rods, ball (beads) or disk shapes (flattened beads).
Cal. - Caliber (inches or millimeters); projectile (bullet) diameter or diameter of some specifically defined point in the bore of a barrel; the nominal or approximate diameter of a bore expressed similarly. NOT the same as a cartridge chambering! Caliber is diameter only. .223 Remington is not a caliber. It is a chambering. The number .223 alone, however is understood to mean the .223 Remington, but literally is a caliber. There are several chamberings that use the .223 caliber of bullet or bore. .30-'06 is a chambering. It uses a .308 caliber bullet.
Cartridge - completed assembly, comprised of a case (the central component), primer (for ignition), powder (primary energy source) and bullet (projectile). The cartridge is placed into the chamber and confined by a breech device for firing.
CCW - concealed carry weapon
Chamber - the portion of a firearm which contains the cartridge at firing.
Chambering - i.e., "This rifle is available in the following chamberings: â€¦"; Specific machined dimensions to the interior rearmost portion of a barrel which results in a chamber that will accept and safely fire one cartridge design only, i.e., .30-'06 Springfield, .270 Winchester, .223 Remington, .38-55 Winchester-Ballard, .45-'70 Government, etc. Although acceptable chamber dimensions are defined and accepted throughout the firearms industry by the ANSI-approved SAAMI, there are many "wildcat" and "improved" variations of standard SAAMI chamberings in use.
Charge - quantity of powder; usually in grains. One avoirdupois pound equals 7,000 grains.
Choke - in a shotgun, the taper in the last few inches of the barrel. This is usually a tightening of the bore to a slightly smaller diameter from the actual gauge measurement of the barrel. Some typical choke names, from least to most taper, are: cylinder (no taper), improved cylinder (or simply: "improved"), modified cylinder ("modified") and full choke ("full"). This is not a complete list, but typical.
CLASS III - Refers to the Class III FFL required to deal in NFA items (full-auto, suppressors, etc.)
Clip â€“ A strip of metal that is used to hold cartridges together to facilitate the loading into (usually) an internal rifle magazine.
CONDITION 1 - Pistol: Full magazine, cartridge in chamber, hammer cocked, safety on. AKA "cocked and locked."
CONDITION 2 - Pistol: Full magazine, cartridge in chamber, hammer down, safety off.
CONDITION 3 - Pistol: Full magazine, chamber empty.
CONDITION 4 - Pistol: Full magazine separate from gun, chamber empty.
Components (reloading) - individual components that make up the "recipe" for a hand loaded cartridge. The four components are: primer, case, bullet and powder.
CRUISER READY - Shotgun: Full magazine, chamber empty, hammer down, safety off.
CUP - copper units of pressure; a method of measuring chamber pressure, most common with shotguns
Cylinder Gap - the distance between the front of the cylinder and the rear of the barrel in a revolver.
DA - double action, as opposed to single action (SA), DA cocks the hammer and positions a cartridge for firing with a single pull, through full travel, of the trigger
DAO - double action only
DEWC - double ended wadcutter (bullet design)
EAA - European American Arms, a manufacturer of firearms
FMJ - full metal jacket (bullet design)
FN - There are several arms factories in different countries which use the initials "FN", standing roughly for National Factory. The best known FN is the Belgian arms manufacturer, Fabrique Nationale d'Armes d'Guerre or National Factory of War Arms, in Leige and Herstal, Belgium.FN was the developer of the Fusil Automatique Leger or Light Automatic Rifle, commonly called the FAL or FN-FAL. FALs are or have been the standard service rifle of a number of countries, including most of the British commonwealth, and were manufactured in several countries. Several semi-auto only versions are available on the U.S. market.Also: flat nose (bullet design)
FP - flat point (bullet design)
FPS - feet per second
FTF - failure to feed/failure to fire
G&A - Guns & Ammo (print magazine)
GA - gauge (also: ga.)
GCA - Gun Control Act (1968)
GC - gas check; a copper-zinc alloy cup used as gilding to protect the base of lead bullets from hot gas obduration during internal ballistics.
H&R - Harrington & Richardson, a manufacturer of firearms
HBWC - hollow base wad cutter (bullet design)
Headspace - measurement between two points in a chamber which are the confining boundaries of cartridge movement during chambering and firing. Insufficient headspace hinders complete chambering of the cartridge. Excessive headspace permits case stretching and can permit case separation, which will permit high pressure gas leakage during the firing/pressure cycle. Very dangerous to equipment and shooter. Headspace is defined and measured differently for each case design. Rimless, rimmed and belted bottleneck cases each have a method unique to the design and a measurement specific to the chambering. Straight walled cases, rimless and rimmed, also have unique methods and cartridge-specific measurements.
HD - Home Defense
Hodgdon - modern gun powder manufacturer
HP - hollow point (bullet design)
IMR - modern gun powder manufacturer: Improved Military Rifle; formerly DuPont
JHC - jacketed hollow cavity (bullet design)
JFP - jacketed flat point (bullet design)
JHP - jacketed hollow point (bullet design)
JMB - John Moses Browning. The designer of some of the best guns ever made.
KYPD - keep your powder dry
LOS - line of sight
LRN - lead round nose (bullet design)
LSWC - lead semi-wad cutter (bullet design)
LWC - lead wad cutter (bullet design)
Mag. - magazine; magnum; also: mag.
Magazine- ammunition holders that are equipped with a spring to move the ammo, these are not clips.
MM - Millimeters; also mm
MV - muzzle velocity, usually in fps. Velocity of the bullet at or very near the muzzle of the barrel
MOA - minute of angle
NAA - North American Arms, a manufacturer of firearms
NEF - New England Firearms, a manufacturer of firearms
NFA - National Firearms Act (1934)
O/U - over/under (shotgun)
OAL - overall length
Ogive - a measure of the curvature forward portion of the bullet. The radius of the ogive is usually expressed in multiples or fractions of the caliber.
PBR - point blank range
PDW â€“ Personal Defense Weapon
POA - point of aim.
POI - point of impact.
PPC - Cartridge designed in 1974 by Dr. Louis Palmisano and Ferris Pindell. Based on the 220 Russian case with a head diameter of .441 - .445. Considered to be the most efficient cartridge design available, the .22 cal PPC and 6mm PPC virtually dominate benchrest accuracy competition in the world today.