The Glossary of Industry terms has been compiled by SAAMI’s Technical Committee to facilitate technical interchanges between members of that committee. It is not intended to provide legal definitions of the terms included, and, in light of further experience, the definitions of these terms may change. It is not intended to be comprehensive since it does not cover the full range of the diversity of the sporting arms and ammunition industry’s products. It is, in other words, a working draft that, it is hoped, may be useful in addressing certain technical matters frequently considered by the Technical Committee and is subject to further change and refinement.
It was the committee’s decision that ONLY industry terms would be included which are unique to the firearms and ammunition industry directly. Optical terms have been omitted for the most part. Common metallurgical terms were not included because they are not unique to the industry. Where there is a common term with a usage unique to our industry, it has, however, been included.
F
FAIL-TO-FIRE
A failure of the firearm to discharge after the trigger has been pulled. It can be one of two types: 1.) a complete misfire, or 2.) a delayed fire.
FALLING BLOCK ACTION
An action in which the breech block moves vertically, or nearly so, inside of the receiver walls. Also called a dropping block.
Also Known As: Dropping Block Action, Drop Block Action, Ballard Action
FEED THROAT
A component which guides a cartridge from the magazine to the chamber.
FIELD LOAD
A shotshell loaded for hunting small game animals and birds.
FILLER WAD
Discs of various shapes and thicknesses used to adjust the volume of the contents of a shotshell.
FIRE CONTROL
The mechanism that utilizes trigger action to release the energy to initiate the primer. It may include but not lmited to the trigger, hammer, sear, disconnector, and/or safety.
Also Known As: Fire Control System
FIREARM
1). An assembly of a barrel and action from which a projectile is propelled through a deflagration of propellant. 2). The serialized portion of a frame or receiver.
FIRING PIN
That part of the firearm mechanism which strikes the primer or the rim of a cartridge to initiate ignition in order to fire the cartridge.
FIRING PIN INDENT
1. The impression made by the firing pin in the primer cup of the centerfire primer or the rim of rimfire cartridges. 2. A measure of the kinetic energy delivered by the firing pin.
FIRING PIN PROTRUSION
The distance the firing pin protrudes from the breech face when it is in its most forward position.
FIVE-IN-ONE BLANK
A blank cartridge that was designed for use in firearms of different calibers. It can be used in caliber 38-40, 44-40, and 45 Colt revolvers and in caliber 38-40 and 44-40 rifles.
FLAKE POWDER
A type of smokeless propellant in the form of thin discs or cut squares.
FLASH HIDER
A muzzle attachment designed to reduce muzzle flash. Also called Flash Suppressor.
Also Known As: Flash Suppressor
FLASH HOLE
1. A hole pierced or drilled through the web in the primer pocket in a centerfire cartridge case. 2. The hole in the end of a battery cup primer used in shotshells.
FLASH SUPPRESSANT
A material that is added to propellant for the purpose of reducing muzzle flash.
FLAT NOSE PROJECTILE
A projectile which is flat at its forward end.
FLAT TRAJECTORY
A relative term for minimal arching in the flight of a projectile. Generally, the faster the speed of the projectile, the flatter it’s trajectory.
FLAT-NOSED BULLET
A bullet with flattened front end perpendicular to the axis.
FLATTENED PRIMER
1. A condition where the normally rounded corners of a fired primer cup are squared due to internal pressures. 2. A primer cup configuration in which the crown is flattened to alter sensitivity.
FLINT LOCK
A muzzleloading firearm ignition system wherein a piece of flint is secured to the hammer in such a manner as to strike steel upon hammer release, causing sparks which ignite powder contained in the ignition system, for subsequent ignition of the main powder charge.
FLOATING CHAMBER
A system in which a rearwardly movable chamber operates the mechanism of a firearm when fired.
FLOATING FIRING PIN
A design in which the forward motion of the firing pin is unrestrained by a spring or other mechanical means.
Also Known As: Free Floating Firing Pin
FLOOR PLATE
The bottom of a box magazine. May be hinged, sliding or immovable.
FLUTED BARREL
A barrel with longitudinal grooves cut into the outside surface for all or some portion of the overall length.
FLUTED CHAMBER
A chamber that has longitudinal grooves.
FLUTING
1. See Oil-Dent. 2. Longitudinal grooves in the sidewall of a firearm chamber. 3. See Fluted Barrel.
Related Terms: FLUTED BARREL, OIL DENT
FLYER
1. A shot considerably outside the normal group on a target. 2. A shot considerably outside the normal range with regards to velocity or pressure.
Also Known As: Stray
FOIL
Part of a primer. See Paper Disc.
Related Terms: PAPER DISC
FOLDING SIGHT
A front or rear sight that can be folded down.
Also Known As: Leaf Sight
FOLLOWER
That part in a firearm which, through the action of a spring, forces a cartridge or cartridges to move.
FORCING CONE
1. The tapered leade from the shotgun chamber diameter to the bore diameter. 2. The tapered leade from the bore diameter to the choke diameter. 3. The tapered entrance to the bore in the rear of a revolver barrel.
FORE-END
Traditionally, the forward portion of a one-piece stock. Sometimes called a Forearm.
Also Known As: Forearm
FORE-END LUG
A protrusion found on the bottom of the barrel(s) (or lower barrel in over/under firearms) that serves as the attachment point of the fore-end. Typically associated with top-break action firearms.
FOREARM
Traditionally, the forward part of a two-piece stock. Sometimes called a Fore-end.
Also Known As: Fore-End
FRANGIBLE BULLET
A projectile designed to readily break up upon impact on a hard surface in order to minimize ricochet or spatter.
Also Known As: Gallery Bullet
FRANGIBLE PROJECTILE
Originally designed for law enforcement training, frangible ammunition’s projectile is designed to break up upon impact with hardened (e.g. AR500) steel into fragments small enough to prevent injury from ricochet/splash-back at typical practice distances. Ammunition loaded with frangible projectiles is sometimes referred to as “Reduced Hazard.”
FREE BORE
A portion of the chamber, usually cylindrical, forward of the casemouth of a diameter larger than the projectile in which rifling is not present. See Bullet Jump. See Throat.
Related Terms: BULLET JUMP, THROAT
FREE RIFLE STOCK
A target rifle stock used for position shooting matches. The word “free” refers to the fact that there are no restrictions on its configuration or weight.
FRICTION RING
A metallic ring surrounding the magazine tube to retard the opening velocity of a recoil operated shotgun.
FRONT SIGHT
Any form of sighting device at or near the muzzle of a firearm.
FRONT SIGHT HOOD
A cover to protect the front sight from damage.
Also Known As: Sight Cover
FRONT STRAP
The exposed metal strip at the front of a pistol or revolver grip.
Also Known As: Strap
FULL LENGTH RESIZING
The operation of reforming a fired cartridge case to approximately its original dimensions.
FULL LENGTH SIZING
The operation of reforming a fired cartridge case to approximately its original dimensions.
FULL METAL JACKET BULLET
A projectile in which the bullet jacket encloses most of the core with the exception of the base. Also called Full-Jacketed, Full Patch, Full Metal Case.
Also Known As: Full Metal Jacket, Full Jacketed Projectile, Metal Cased Bullet, Metal Patched Bullet
FULL-COCK
The position of the hammer or striker when the firearm is ready to fire.
FUSED SHOT
Two or more shot pellets joined together during the process of manufacturing or during firing.