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.
A scaly appearing area indicative of lamination caused by contamination of cartridge case brass.
A stock which is made from two or more pieces of wood which have been glued together longitudinally.
The uncut surface of the bore of a rifled barrel.
A strap or cord that is attached to a firearm (usually handgun) and worn around the neck or shoulder to prevent loss of the firearm.
The process of polishing a metal surface such as the interior of a barrel with a fine abrasive substance.
Also Known As: Lapping
A movable device used to secure a part or piece in place relative to another. As applied to firearms, various types of latches are employed to hold barrels, cylinders, etc., in position and to enable these parts to be moved for loading, unloading and disassembly.
Also Known As: Bolt
A bullet formed by a lead alloy.
LEAD KNIFE GROOVE
A circumferential impression in a lead bullet applied forward of the mouth of the case after crimping.
Spherical pellets used in loading shotshells. Commonly formed from lead but may be made from steel.
Also Known As: Drop Shot, Chilled Shot
The accumulation of lead in the bore of a firearm from the passage of lead shot or bullets. Also called Metal Fouling.
Also Known As: Metal Fouling
LENGTH OF PULL
See Stock Dimensions.
LENGTH OF STOCK
See Stock Dimensions.
A projecting piece used to operate a mechanism, as the lever of a lever action firearm. See also, Lever Action.
An action in which an external lever generally below the receiver, cycles the breech bolt on a horizontal or nearly horizontal plane in line with the barrel.
A device intended to hold the lever closed on some lever action guns.
Insufficient firing-pin energy or protrusion resulting in failure to ignite the primer.
Also Known As: Light Strike, Light Blow, Light Hit
A form of engraving in which the entire pattern or design consists of shallow line cuts as opposed to engraving done in bas-relief. This type of engraving is often found on the metal parts of firearms.
LINE OF DEPARTURE
The direction in which a projectile is moving when it leaves the muzzle of a firearm. Also defined as the tangent to the trajectory at the muzzle. See Trajectory.
LINE OF SIGHT
A straight line drawn from the shooter’s eye, passing through the sights of a firearm and extending from the firearm to a target.
Also Known As: Line of Sight
1. A part in a firearm that connects two other parts, while permitting flexibility between the parts. 2. The individual interlocking pieces that form the belt for belted ammunition.
A connection between parts used to transmit motion from one to the other.
If a bullet is incorrectly inserted into the mouth of a case, it may deform the case mouth rearward, downward, causing a defect. Also known as a Tear-Down.
Also Known As: Tear-Down
A metallic cartridge or shotshell that is complete and ready to use.
Also Known As: Live Ammunition, Fixed Ammunition
1. The combination of components used to assemble a cartridge or shotshell. 2. The act of putting ammunition into a firearm.
A device containing a number of blind holes into which cases or completed ammunition are placed.
The relationship, in a cartridge, of the volume of the propellant to the available case volume. Usually expressed as a percentage.
1. Revolvers: A hinged piece attached to the frame which is opened to permit loading. 2. Shoulder Arms: A spring loaded cover for the loading port.
The opening in a receiver where a cartridge may be placed in the firearm either directly into the chamber or the magazine.
A platform or cut placed in the bottom of the receiver that aids in guiding a cartridge into the chamber as the action is closed.
1. A general term referring to the total firing mechanism in a firearm. 2. Range command sometimes used to indicate engagement of a manual safety (“Lock your firearms”). 3. An accessory intended to help secure a firearm from unauthorized use.
Also Known As: Gun Lock
The amount of energy delivered to the primer from the firing-pin blow.
A device incorporated into the mechanism of some firearms where the barrel and the bolt assembly recoil upon firing. The lock frame acts to absorb the shock of the recoiling parts prior to the bolt unlocking and opening.
A metal plate mounted on the stock of a gun to provide for mounting of, or access to, the firing mechanism.
LOCKED BREECH ACTION
An action in which the breech bolt is locked to the barrel or receiver, until unlocked through a mechanical process.
Also Known As: Locked Breech Action
The firearm component designed to secure the action in the locked position.
Also Known As: Locking Bolt
An incline, either helical or straight, to assist in closing the action on a chambered cartridge.
The time interval between sear release and the firing-pin striking the primer.
1. Originally, the term was used in reference to long-barreled flintlock rifles. 2. The name given one type of a caliber 22 rimfire cartridge.
A primer which does not fit properly in the primer pocket of a cartridge case or shotshell.
LOT OF POWDER
A homogeneous blend of powder having defined chemical and physical properties, as well as performance characteristics.
A term commonly applied to a shotshell with a low metal cup, but properly applies to the height of the internal base wad. Often misused as synonymous with low brass or low cup.
Common terminology referring to the length of the external metal cup on a shotshell.
Also Known As: Low Brass, Low Cup
Correct term for shotshells having a low metal head type of construction.
See specific type: Bullet, Inside Lubricated Bullet, Outside Lubricated.
A circumferential groove in a projectile for the purpose of holding lubrication.
One of several projections located on the underside of the barrel or barrels on break action guns, which serves to secure the barrels to the action or receiver. See Barrel Lug.
Related Terms: BARREL LUG
LUP (LEAD UNITS OF PRESSURE)
(Obsolete) A pressure value determined by means of lead crusher cylinders.