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.
The acronym for the Sporting Arms and Ammunition Manufacturers’ Institute.
(Pronounced saˈbō or ˈsabō) A carrier for firing a sub-caliber projectile in a larger bore firearm. The sabot is intended to seal the bore and center the sub-caliber projectile in the bore. In most circumstances the sabot separates from the projectile after exiting the barrel.
Also Known As: Sabot Type Projectile
A ring usually attached to the receiver of a firearm designed to be carried by a horseback rider.
An incorrect generic term for Safety.
SAFE CARRYING CONDITION
The condition in which it is contemplated that a particular design of firearm is to be carried.
Precautions taken by firearms users to help provide protection against accidental or unintentional discharge.
A device on a firearm intended to provide protection against unintended discharge under normal usage when properly engaged.
1. “On” – A term describing the position of a component of the safety device when set in a manner to provide protection against unintended discharge under normal usage.
2. “Off” – To allow the firearm to be discharged.
A German term for a hook shaped knob at the forearm tip of a stock.
Also Known As: Schnabel Fore-End
An extremely concave metal butt plate with a rearward extension usually at the bottom used mostly on target rifles for offhand (standing) shooting.
A sight containing optical elements which may or may not magnify or enlarge the target.
Also Known As: Telescopic Sight, Riflescope
A part which retains the hammer or striker in the cocked position. When released, it permits firing.
A term used for stress-corrosion cracking that involves metallic cases or shotshell cups with both residual stress and specific corrosive agents.
The positioning of a primer or bullet in a metallic cartridge case or a wad in a shotshell.
The longitudinal position of a bullet, primer or wad in a cartridge case.
A projectile nose with the curvature not tangent to the cylindrical bearing portion.
The ratio of bullet weight to its diameter.
SEGMENTED CRIMP COLLET CRIMP
A method of securing a bullet into a metallic cartridge case by using a chuck (collet) to exert a clamping force around the mouth of the shell case.
SELECTIVE SINGLE TRIGGER
An arrangement on double-barrel firearms having a single trigger which enables the shooter to choose the barrel he wishes to fire first. The mechanism will then subsequently switch to the unfired barrel, which a second pull of the trigger can then fire.
1. In a double barreled gun, a device to allow the shooter to choose which barrel is to be fired by the first pull of the trigger. 2. A lever which enables the shooter to choose the type of fire, semi-auto or full auto, with high or low rate of automatic fire.
An action, typically a magazine-fed repeating, in which the action is manually opened after each firing, which captures energy in a storage system, typically an action spring. Manually opening the action causes the fired case to be extracted from the chamber and ejected from the firearm. After opening, the stored energy is utilized to close the action and, in the instance of a repeating firearm, feed another cartridge into the chamber.
An action in which each pull of the trigger results in a complete firing cycle from discharge through reloading. It is necessary that the trigger be released and pulled for each firing cycle. Also called Autoloader or Self-Loader. For Blowback Operated: See Blowback Action. See Delayed Blowback Action. For Recoil Operated: See Recoil Operated Action. For Gas Operated Action: See Gas Operated Action. For Inertia Operated: See Inertia Operated Action
Also Known As: Semiautomatic
An action, either single shot or magazine-fed repeating, that uses the energy of the fired cartridge to open the action after the firing of a cartridge. In opening, the fired case is extracted from the chamber and ejected from the firearm. Opening the action captures energy in a storage system, typically an action spring, and the action locks in the open position. The user must manually activate a mechanism that releases the stored energy to close the action and, in the case of a repeating firearm, feed another cartridge into the chamber. As applied to a single shot firearm, a cartridge must be manually loaded into the action/chamber before the release mechanism is actuated for subsequent firings.
The term for a stock which has been rough shaped and partially or completely inletted.
A firearm stock that has been machine inletted and requires additional hand fitting to achieve proper fit. Also called Rough Inletted.
Also Known As: Rough Inletted Stock
A bullet with a partial jacket exposing a lead nose.
SEMI-JACKETED HOLLOW POINT BULLET
A projectile having a jacket exposing a lead nose with a cavity.
A centerfire cartridge having a case head only slightly larger in diameter than the case body and an extractor groove just forward of the head.
Also Known As: Semi-Rimmed Cartridge
A projectile with a distinct shoulder and short truncated cone at the forward end.
Also Known As: Semi-Wadcutter
Firearm which fires, extracts, ejects and reloads once for each pull and release of the trigger. Also called Self-loading or Auto-loading.
Also Known As: Self-Loader, Self-Loading, Auto-Loading
A self-loading, magazine-fed firearm in which each pull of the trigger results in a complete firing cycle from firing through loading. It is necessary that the trigger be released and pulled for each firing cycle. See
Also Known As: Semiautomatic, Auto-Loader
Related Terms: SELF-LOADER
SENSITIVITY TEST FOR PRIMED SHELLS OR PRIMERS
A method of determining the sensitivity of primed cases held in a specified die and subjected to a range of specified firing-pin blows imparted by a freely falling ball. Commonly called Drop Test.
Also Known As: Drop Test, Primer Drop Test
A number applied to a firearm by the manufacturer in order to identify the individual firearm.
A trigger having longitudinal grooves on its face.
Narrow parallel grooves cut into a surface to provide a gripping surface or to break up light reflections.
Commercially loaded, sporting ammunition, intended to meet the full service requirements of the targeted consumer.
Also Known As: Service Cartridge
1. Commercially available sporting ammunition. (As opposed to proof, reference, etc., or other special use ammunition). 2. Ammunition carried by Police Officers on duty. Also, ammunition carried by soldiers in combat, as opposed to special service ammunition, i.e. Match, Armor-piercing, etc.
Also Known As: Ammunition Service
Either a single or double trigger arrangement on which the required trigger pull force can be made very light by means of “setting” mechanism. May be either Double Set trigger or Single Set trigger.
The arming of a set-trigger mechanism of a firearm so equipped. See Set Trigger.
Related Terms: SET TRIGGER
A trigger which has a minimum projection from the action and is not usually surrounded by a trigger guard. Also called Spur Trigger.
Also Known As: Spur Trigger
Generic term for the unloaded case for metallic or shotshell ammunition. A colloquial term incorrectly used for loaded ammunition.
A device for catching fired shells.
A device for holding the head of a cartridge case in a reloading tool.
The disturbance of air surrounding and behind the bullet caused by a compression of the air column directly in front of the bullet.
A colloquial term used to describe the ability of a projectile to dissipate its kinetic energy effectively in a target.
1. A metallic adapter fastened to a trigger to widen the surface. 2. A metallic insert in the forearm of a side-by-side double barreled shotgun by which the forearm is attached to the barrels. Also called Fore-end Iron, Fore-end Plate.
Also Known As: Fore-End Iron, Fore-End Plate
The separation of the mouth end of a shotshell from the body when it is fired.
Eye protection and sight improvement specifically designed for, and which should always be used, when shooting firearms.
A type of 22 caliber rimfire cartridge.
A cartridge in which the bullet is seated below the specified minimum length.
Spherical pellets used in loading shotshells. Commonly formed from lead but may be made from steel or other material.
A wedging action of shot pellets in a tube causing a stoppage of flow in a shotshell loading operation.
A centerfire or rimfire cartridge loaded with small diameter shot.
The length of the shot load in a shotshell.
A device attached to the muzzle of a shotgun to provide oval shot patterns.
A numerical or letter(s) designation indicating the average diameter of a pellet. With numerical designations, the average pellet diameter may be determined as follows: Shot Size = (17 – Number Designation)/100 For example, for No. 6 shot: (17-6)/100 = 0.11” 17 – Designation Number = Avg. Shot diameter in hundredths of an inch 100 EXAMPLE: For No. 10 Shot: 17-10 = 7/100 = .07”
The distance between the leading and trailing pellets of a shot charge in flight.
A tall building in which molten lead alloy is dropped through a colander near the top of the tower into a tank of water at the bottom to produce spherical pellets.
A plastic or paper insert surrounding the shot charge in a shotshell to reduce distortion of the shot when passing through the barrel.
Various designs of shot cups made of plastic and designed to reduce pellet deformation during barrel travel.
Also Known As: Shot Cup
A smooth bore shoulder firearm designated to fire cartridges containing numerous pellets or a single slug. In some cases, shotgun bores are rifled to be used specifically with slugs.
Any stock used on a shotgun. See Two Piece Stock.
Related Terms: TWO PIECE STOCK
A round of ammunition containing multiple pellets for use in a shotgun.
1. Act of placing a shotgun or rifle to a shooter’s shoulder, in order to properly align the sights and fire at a target. 2. The sloping portion of a metallic cartridge case that connects the neck and the body of a bottleneck-type cartridge. 3. The square or angular step between two diameters on a barrel, pin, stud or other part commonly used in sporting firearms.
The curved surface between the body and the shoulder of a cartridge case.
A longitudinal rupture in side wall of the shoulder of a bottlenecked cartridge case.
Any firearm fitted with a stock and designed to be used while held with both hands and supported by a shoulder.
Also Known As: Long Gun
SIDE LOCK ACTION
An action in which the fire control system is attached to a side plate rather than being integral with the frame or trigger plate.
Also Known As: Action Bar Lock
SIDE PIN OR SCREW
Screw used to attach side-locks to frame and/or stock.
A firearm with two barrels arranged adjacently in the horizontal plane.
A firearm with the hammer located externally on the side of the frame as contrasted to an internally pivoted hammer.
A form of firearm construction that has the firing mechanism mounted on detachable plates on the side.
A removable plate in the frame or receiver to allow access to internal parts or upon which some internal parts are mounted.
A handgun (pistol or revolver).
Any of a variety of devices, mechanical or optical, designed to assist in aiming a firearm.
The movement of a sight to change the point of impact.
The hole in the disc of an Aperture Sight. Aperture Sight
Related Terms: APERTURE SIGHT
That part of a sight that is usually attached to a gun.
The small cylindrical top portion on some forms of front sights.
1. (Front sight) An elongated projection usually mounted parallel to the bore, used as the front sight on some firearms. See Blade Sight. 2. (Rear sight) An elongated movable portion of an adjustable rear sight that incorporates the sighting notch or aperture.
Related Terms: BLADE SIGHT
Protective metal cover fastened about a sight to guard it from being moved out of adjustment from jars or blows. Sometimes called a Sight Hood or Hooded Sight.
Also Known As: Sight Hood, Hooded Sight
That part of an aperture (peep) sight that contains the hole. May have either a fixed orifice or contain an iris diaphragm to vary its size.
The height to which a rear sight is set to zero-in the firearm for any specific range.
A device that increases the distance between the sights.
Metal or plastic discs with either apertures or posts for use in globe front sights.
The vertical portion of a metallic rear sight containing the notch.
The visual image observed by the shooter when the firearm sights are properly aligned on the point-of-aim.
Also Known As: Sight Alignment
The distance between the rear sight and the front sight on a firearm.
A sight base having a sloping rear surface on which a front or rear sight may be mounted.
The procedure of adjusting the sights so as to bring the point of impact to coincide with the point of aim.
Also Known As: Zero-In
Shot(s) fired to determine point of impact.
A firing mechanism in which the trigger serves the sole purpose of releasing the firing mechanism – either hammer or striker. For differentiation: See Double Action. See Double Action Only.
SINGLE ACTION PISTOL
A pistol mechanism which requires the manual cocking of the hammer or striker before pressure on the trigger releases the firing mechanism.
SINGLE ACTION REVOLVER
A type of revolver in which the hammer must be cocked manually to rotate the cylinder for each shot. The firearm is then discharged by a pull of the trigger. The process is repeated for each shot.
SINGLE BASE POWDER
Smokeless propellant powder which has colloided nitrocellulose as its main ingredient, and contains no other major energy-producing component. The nitrogen content of the nitrocellulose is usually between 13.1% and 13.2%. In the United States, single base powders contain no nitroglycerine, whereas in some European countries powders containing less than 10% nitroglycerine are considered single base. See Double Base Powder for comparison.
Also Known As: Nitrocellulose Powder
Related Terms: DOUBLE BASE POWDER
SINGLE POINT SLING
A strap design that attaches to only one point on the firearm.
A firearm with no means in the mechanism for storing or loading more than a single cartridge housed in the chamber of the barrel.
SINGLE SHOT ACTION
An action that will only accept a single cartridge that must be manually loaded into the firearm’s chamber each time it is fired.
Also Known As: Single Shot
SINGLE STAGE TRIGGER
1. A trigger mechanism in which the trigger travel is relatively short and there is no significant sensible change in pull force from the beginning of movement up to the point of firing. 2. A trigger which releases with a single pull.
A trigger mechanism for multiple barrel firearms wherein repeated pulls of one trigger fires the barrels successively.
A type of trigger mechanism found on some double-barrel or over-under shotguns consisting of two triggers. The front trigger functions as a conventional non-selective single trigger, while the rear trigger will fire only the barrel with the tighter choke.
SIX O'CLOCK HOLD
A sight picture where the top of the sight is tangent to the bottom of the bullseye.
1. The reduction in diameter of a bullet by forcing it through a die of smaller diameter than the bullet. 2. The reduction in diameter of a cartridge case by forcing it into a die of smaller diameter than the case.
Also Known As: Bullet Sizing, Cartridge Case Sizing
A tool used to form a cartridge case or bullet to proper dimensions.
A shotgun with a choke of minimal constriction specifically designed for Skeet shooting or may also be used for close range game hunting.
A shotgun target sport in which shooters move around a semi-circle and fire at clay targets thrown at specified angles and from a high and a low “house”, each containing a target trap.
SKELETON BUTT PLATE
A metal buttplate forming only a border for the butt.
Longitudinal rifling marks formed on the bearing surface of bullets as they enter the rifling of the barrel before rotation of the bullet starts.
Also Known As: Rifling Marks
A type of gunstock line engraving where lines are omitted at regular intervals. Also called Skip-a-line, or Skip-Line, or French checkering
Also Known As: French Checkering, Skip-a-Line, Skip-Line
A special substitute action used for testing a barrel or barrels.
A pin used during assembly of a firearm to facilitate the process and later replaced by a permanent pin or screw.
1. A means of renewing old shotgun barrels by insertion of a tube into the bore or interior of the barrel. 2. A tube surrounding the receiver of a target rifle to improve rigidity. 3. The shot container in a shotshell. 4. The inner, rifled portion of a two-piece barrel.
Also Known As: Barrel Sleeve
A member attached to and reciprocating with the breech block.
Also Known As: Pistol Slide
SLIDE LOCK, ACTION BAR LOCK
The part of a mechanism, normally found on slide action firearms that locks the forearm/slide mechanism in the forward position.
Device to retain slide in an open position.
A manual safety mechanism on a firearm that is operated by a longitudinal sliding motion.
Also Known As: Tang Safety
A strap detachably fastened to a firearm to assist in carrying or to steady it during firing.
Also Known As: Rifle Sling, Strap
A dovetail-shaped metal part to occupy an unused dovetail slot.
A cleaning rod tip with a slot to hold a cleaning patch.
A single projectile fired from a shotgun. Also slang term for bullet after it has been fired from a firearm.
A process of determining the interior dimensions of a barrel or cylinder by measuring a deformable material which has been pressed through the bore.
Also Known As: Bore Slugging
A term that has numerous definitions (military, political, regulatory etc.). For the purpose of firearms that fall under SAAMI: See Sporting Arms.
SMALL BORE CARTRIDGE
General term applied in the United States to 17 and 22 caliber rimfire cartridges. Normally used for target shooting and small game hunting.
SMALL OF THE STOCK
That portion of the stock between the rear of the action and the comb, which has the smallest circumference.
Also Known As: Wrist
In America, any firearm or ammunition of the rimfire type with a lead alloy bullet not over 0.23” in diameter.
A propellant containing mainly nitrocellulose (single base) or both nitrocellulose and nitroglycerine (double base).
Firearm with unrifled bore, typically a shotgun.
A protective device to permit dry firing without damage to the firing-pin.
SOFT POINT PROJECTILE
A design providing for exposure of a portion of the core at the nose of a jacketed bullet, to initiate expansion of the projectile upon impact.
Also Known As: Soft Point Bullet
1. In shoulder arms, a firearm in which the barrel and receiver are not designed for quick disassembly. 2. In handguns, having a frame that is not hinged.
A solid raised surface above a barrel or barrels which functions as a sighting plane.
SPEED OF ROTATION (SPIN)
The rate of spin of a projectile fired from a rifled barrel.
A bullet which has lost all of its kinetic energy.
Also Known As: Spent Bullet, Spent Slug
Smokeless Propellant manufactured by a process in which nitrocellulose is first lacquered with solvents then being processed into a sphere. The finished product may take the form of a sphere, flattened sphere, or cylinder.
The deviation from the expected flight path of a bullet due to the gyrational spin of bullet imparted by the rifling.
SPIRE POINT PROJECTILE
A pointed projectile characterized by a sharply secant ogive or a conical nose profile.
Also Known As: Spire Point Bullet
A pointed projectile characterized by a long tangent or slightly secant ogive.
Also Known As: Spitzer Bullet
A longitudinal split in the sidewall of the brass or steel cup assembled on a plastic or paper shotshell.
Also Known As: Cup Split
A longitudinal rupture in the neck of a metallic cartridge case.
Also Known As: Neck Crack
SPLIT RIM (RIM-SPLIT)
A circumferential rupture of the rim of a rimfire cartridge or shotshell.
The act or process of converting a military weapon to a sporting firearm, usually by removing unneeded accessories, and altering the barrel and/or stock.
Sporting arms are generally considered rifles and handguns up to and including 50 caliber and shotguns up to and including 10 gauge, with some limited exceptions pertaining to caliber, gauge, or type.
SPORTING ARMS AMMUNITION
Ammunition for Sporting Arms. See Sporting Arms.
Related Terms: SPORTING ARMS
A shotshell load specifically designed to provide a widely spread pattern at a close range. Also called Scatterload, Bush Load, Thicket Load.
Also Known As: Brush Load, Thicket Load, Bush Load, Scatterload
Handle of a revolver with a flat or squared end.
A cartridge or shell which produces projectile velocity and sound substantially lower than normal. May result in projectile and/or wads remaining in the bore.
Also Known As: Squib
A method of securing a bullet or primer into a metallic cartridge case by means of multiple indentations.
A method of securing a primer into a metallic cartridge case by deforming the primer pocket mouth inward.
An industry term for rimfire ammunition loaded to a velocity level below high velocity ammunition of that type.
The fixed vertical face of a frame, typical of a break-open firearm, which contains the striker(s) or firing pin(s).
A type of closure of the mouth of a metallic case or shotshell in which the sidewalls are folded in a star-shaped pattern.
Also Known As: Rose Crimp, Pie Crimp
A measuring instrument for determining internal diameters, often used to measure the inside diameter of a gun barrel.
A projection at the end of a mainspring which fits into the lock plate of a side lock action gun.
STEEL JACKETED BULLET
Plated or clad steel is sometimes used as a substitute for gilding metal or copper in bullet jacket material.
Soft steel pellets made specifically for use in shotshells.
A failure of a cartridge to feed in which the bullet jams against the top or bottom of the chamber. Also called Cock-Up or Cock-Down.
Also Known As: Cock-Up, Cock-Down
The roughing of wood or metal with a pointed tool. It is normally performed to provide a gripping or decorative surface. Also called Matting.
Also Known As: Matting
A component with divided legs to apply force equally. Mainly used in a trigger assembly where it is necessary to straddle another component.
The wood or plastic component to which the metal parts of a firearm are attached to enable the shooter to hold the firearm.
A bolt which passes through a buttstock lengthwise to secure it to the receiver or frame.
General stock dimensions consist of the following: length of pull, drop at comb, drop at Monte Carlo, drop at heel, pitch and cast.
A. Rifles 1. Cast is the lateral displacement of the centerline of the buttplate (pad) from the centerline of the bore. For a right-handed shooter, when the centerline of the buttplate is to the left of the bore, it is expressed as cast-on and to the right as cast-off. The opposite is true for left-handed shooters. 2. Drop is the vertical distance from the line of sight to the comb, Monte Carlo or heel of the stock. It is measured from an extension of a straight line drawn from the top of the front sight through the top surface of the open rear sight adjacent to the notch. The drops for target rifles are usually measured from the centerline of the bore. 3. Girth – The smallest circumferential dimension at the pistol grip. 4. Length of Pull – The distance from the center of the trigger to the center of the buttplate or recoil pad. 5. Length of Stock – The greatest dimension of the stock material. 6. Pitch – Not usually given for rifle.
B. Shotguns 1. Cast – Same as A.1., above. 2. Drop is the vertical distance from the line of sight to the comb, Monte Carlo or heel of the stock. It is measured from an extension of a straight line drawn from the base of the front bead sight across the highest point on the frame or receiver. 3. Girth – Same as A.3., above. 4. Length of Pull – same as A.4., above. 5. Length of Stock – Same as A.5., above. 6. Pitch is an expression used to indicate the relationship of the bore to the plane of the buttplate (pad). It is found by extending a line across the butt and drawing at right angles to this line an additional line through the highest point on the receiver or frame and measuring the distance from an extension of this line to a point at the base of the front sight bead. The pitch is said to be if the described line is above the front sight and if below. The pitch is normally down.
Also Known As: Drop at Comb, Drop at Heel, Drop at Monte Carlo, Cast
The angle at which the buttplate or recoil pad slopes in relation to the bore axis. For method of measuring, see Stock Dimensions.
A screw used for attaching the stock to the receiver or frame of a firearm. More than one may be used per firearm.
The twisting and bending of a wood stock due to moisture absorption.
STOCKMAKER'S HAND SCREWS
Extra long screws used by stockmakers during the inletting operation to maintain alignment of the trigger guard and other auxiliary items with the action. Also known as Inletting Screws or Guide Screws.
Also Known As: Inletting Screws, Guide Screws
This term is used when a firearm stops firing due to a malfunction of either the gun mechanism or ammunition. This term is normally used in connection with automatic firearms, machine guns, etc.
A failure to eject where the fired case is caught in the ejection port by the forward motion of the bolt The case protruding upward out of the ejection port is said to resemble an old fashioned stove pipe.
On shoulder firearms, describes a butt stock without a pistol grip.
Also Known As: English Stock
A bolt action firearm in which the bolt need not be rotated to open or close the action but is reciprocated by a straight backward and forward motion of the shooter’s hand.
1. A stock with no pistol grip also known as an English Stock. 2. A “Cast-Neutral” Stock.
Also Known As: English Stock, Straight Grip Stock
An electronic device to measure stress and strain in mechanical devices.
A screw which bears against a leaf spring and by its movement in or out will change the tension of the spring.
A spring-driven rod-like firing pin, or a separate component which impacts the firing pin, which travels in a linear path to strike the primer.
The velocity of a projectile at the point of impact.
Related Terms: TERMINAL VELOCITY
To disassemble a firearm in order to clean, repair or transport it. “Field stripping” is simple disassembling for cleaning; “detail stripping” is a complete disassembly of the firearm into it’s components.
A receiver or frame of a firearm from which all parts have been removed.
1. The act of disassembling a firearm. 2. The act of transferring cartridges from a loading (“stripper”) clip to the magazine. 3. Failure of a bullet to engage the rifling properly.
Related Terms: TAKE DOWN
A button-type trigger, the end of which is pressed to fire the firearm.
A cartridge having a projectile smaller than is standard for the firearm in which it is used.
An adaptation to a firearm to enable the firing of smaller or lower powered ammunition for which it was originally intended.
A tube which is place in the bore of a firearm to enable the firing of smaller or lower powered ammunition.
Also Known As: Barrel Insert
A wood finish which is achieved by scorching to give a darkened and grainy appearance.
The velocity of a projectile at the highest point of the trajectory.
A device attached to the muzzle of a firearm to reduce the noise of discharge. Sometimes called a silencer.
Also Known As: Silencer, Sound Suppressor
A bullet that has been completely formed by impacting the bullet material into a die.
A shotgun barrel constriction which has been formed at or near the muzzle by the use of dies or hammers.
That part of a swivel which is in the form of an elongated loop and to which a sling or carrying strap is passed through or otherwise attached.
A metallic loop to which the sling is attached.
Also Known As: Sling Swivel