Handgunner's Glossary

By Jan Libourel


Stands for "Automatic Colt Pistol." Used to designate certain cartridges first chambered in Colt automatic pistols--.25 ACP, .32 ACP, .380 ACP, .38 ACP, .45 ACP

Action Shooting:

A generic term for a variety of shooting games usually characterized by extreme speed of fire, relatively powerful handguns, medium to large targets and short to medium ranges. Often called "Combat Shooting." IPSC-style competitions, bowling pin and falling plate matches are all typical of this type of shooting.

Bevel Base:

Any bullet design in which there is a slight bevel (to facilitate cartridge reloading) between the base and the bearing surface proper. (Opposed to Plain Base)


An operation system in self-loading firearms in which the slide or breechblock is driven to the rear by direct gas pressure on the cartridge case head.


A device for holding cartridges together, usually to facilitate loading. Widely used as a synonym for "magazine" (although most firearm authorities consider this substandard usage). Technically, a magazine has a feeding spring, a clip does not.

Cocked And Locked:

The practice of carrying a self-loading pistol with a round in the chamber, the hammer cocked and the safety engaged. (CONDITION ONE)

Condition One, etc:

A system devised by Jeff Cooper for enumerating carry modes for the Colt 1911 and similar auto pistols. Condition One is cocked and locked; Condition Two is hammer down with a round in the chamber; Condition Three is with a loaded magazine, empty chamber; Condition Zero is with a round in the chamber, hammer cocked, safety disengaged.


The swinging unit that hinges the cylinder of a revolver with the frame.


Copper Units of Pressure. The units by which cartridge breech pressures are measured through compression of a copper crusher gauge. Similar but not identical to the older pounds per square inch (psi) system of measurement.

Delayed Blowback:

A variant of the blowback principle in which the blowback operation is by some means retarded (e.g., by a fluted or grooved chamber).


Most commonly, a device in auto pistols that prevent the pistol from being fired until the breech is completely shut and prevents the pistol from being fired fully automatic.

Double Action:

A type of lockwork in either a revolver or auto pistol that permits the hammer to be cocked either by direct manual action or by a long pull on the trigger. The term is extensively used (somewhat erroneously) as a synonym for "trigger cocking." Thus, such phrases as "The double-action pull was very smooth" or "The Seecamp is a double-action-only auto pistol."

Driving Bands:

Portions of a bullet's bearing surface that actually contact the bore. Driving bands are separated by crimping and lubrication grooves.


A device for expelling a fired cartridge case from a firearm.

Flash Gap:

The distance between the face of a revolver's cylinder and the breech end of the barrel. U.S. industry standards call for a gap of .006-inch, with a .003-inch tolerance in either direction.

Floating Firing Pin:

On a revolver, a firing pin that is mounted inside the frame, as opposed to being pinned to the hammer.

Forcing Cone:

The portion at the breech of a revolver's barrel that tapers into the rifling.


Stands for Full Metal Jacketed. A bullet completely enclosed (except for the base) in a hard metal jacket (usually an alloy of copper, sometimes a mild steel). This is the only type of bullet permitted in warfare.


Stands for "feet per second," by which bullet velocity is measured.

Gas Check:

Copper-alloy cups affixed to the bases of specially designed cast bullets with the intention of reducing deformation of the base under high heat and pressure and thus reducing leading.

Gas Operated:

A system of operating an automatic or semi-automatic firearm in which a portion of the powder gasses is bled off from the barrel and used to activate a piston or similar device that cycles the breechblock or slide.

Gas Retarded:

A type of delayed blowback operation in which a portion of the powder gasses is bled off from the barrel to retard the rearward travel of the slide--used in the Heckler & Koch P7 series of 9mm pistols.

Grip Safety:

A device that prevents a handgun from being fired unless it is firmly gripped.


A popular designation for the 230-grain full metal jacketed round-nosed military load for the .45 ACP. By extension, loads using similar bullets in the other auto pistol calibers.


A comic term for a Colt Single Action Army or similar revolver.

Inertial Firing Pin:

A firing pin that is too short to contact the cartridge's primer when the hammer is resting on it and can only hit the primer when driven forward under the momentum of the hammer blow. The system used in the Colt 1911 is an example of an inertial firing pin.


International Practical Shooting Confederation. The governing body for much of the action/combat shooting competition conducted worldwide. Often used as a term for this type of competition. IPSC's American affiliate is the United States Practical Shooting Association (Dept. GAH, Box 811, Sedro Woolley, WA 98284)


Stands for Jacketed Hollow Cavity, a proprietary name used by Sierra Bullets for their line of Jacketed Hollow Point bullets.


Stands for Jacketed Hollow Point, a bullet similar to a Jacketed Soft Point, except that a portion of the nose cavity is hollowed out for greater bullet expansion.


Stands for Jacketed Soft Point, a type of bullet with a soft lead core enclosed by a hard metal jacket (usually an alloy of copper), but with the nose section exposed to ensure bullet expansion.

K Frame:

Most firearms makers have special designations for their various frame sizes, but only the Smith & Wesson revolver frame designations seem to be in general currency these days. Modern Smith & Wesson revolvers are made on four sizes of frames: the J (small), K (medium), L (medium-large) and N (large). Formerly there was the I frame, superseded by the slightly longer J frame, and many years ago the petite .22 "Ladysmith" revolvers were made on an M frame.

Locked Breech:

A firearms action in which the barrel and breechface remain locked together during the initial part of the firearm's discharge. Most powerful auto pistols use the locked-breech principle; most low-powered ones are blowbacks.


A holder for cartridges to be fed into the chamber of a firearm. Usually, but not always, detachable in handguns. (Cf. CLIP)

Magazine Safety:

Also called a "magazine disconnector." A device that prevents a pistol from being discharged when the magazine is removed. (Warning: These devices are not always reliable.)


The spring that powers a handgun's firing mechanism.


The Colt-Browning United States Government Model of 1911 .45 automatic pistol. Loosely, any pistol that uses the same design.


Means "prepare for war." From a Latin maxim--si vis pacem, para bellum--"If you want peace, prepare for war." The European designation of the Luger pistol and (today more commonly) the 9mm cartridge it chambered.


Originally, a dueling pistol. In contemporary usage, a Colt Single Action Army revolver or a derivative.


Stands for Practical Pistol Course, a course of fire developed by the FBI that involves shooting at man-silhouettes from a variety of ranges and shooting positions. Shot competitively, usually by police. The custom heavy-barreled revolvers favored in these competitions are known as "PPC revolvers."

Pin Gun:

A heavily customized auto pistol with a muzzle extension that serves as a weight and recoil compensator. Origninally developed for bowling pin shooting, hence the name. Now universally used in action shooting sports.


Originally, any firearm designed to be fired one-handed. In contemporary American usage, the term "pistol" is limited to handguns in which the barrel and chamber form a single unit, i.e., self-loaders and single shots. It is considered erroneous to apply the term "pistol" to a revolver. However, this distinction is of fairly recent origin. Colt referred to its revolvers as "pistols" at least into the 1880's, and the British military officially designated their service revolvers as "pistols" as late as the WWII era. The origin of this word is particularly obscure. Some trace it to the Italian town of Pistoia, an early gunmaking center. Another explanation derives from a Bohemian handgun called a "pist'ala" from a Czech word for "pipe." Several other more fanciful etymologies exist.


May mean either lowering the ejection port of a self-loading pistol to ensure greater reliability and less damage to cases or the practice of drilling gas vents in a barrel to reduce muzzle jump. The proprietary Mag-na-port system is a well-known example of this.

Recoil Operated:

A form of locked-breech semi-automatic operation in which the barrel and breech remain locked together during the peak pressure, then move rearward under recoil to effect unlocking. Most high-power pistols use this system.

Recoil Shield:

The enlarged portion of a revolver's frame immediately behind the cylinder.

Recoil Spring:

The spring that returns a self-loading firarm's action into battery after firing.


Any handgun whose cartridges are contained in a multi-chambered revolving cylinder separate from the barrel. (Cf. PISTOL)


The portion of a firing mechanism that holds a hammer or striker cocked.

Semi-Wadcutter (SWC):

A bullet with a flat-ended nose section and a full-caliber cutting shelf. The designs of Elmer Keith are famous examples of semi-wadcutter bullets.

Silhouette Shooting:

The competitive sport of knocking over metallic silhouettes of animals with a rifle or handgun, usually at relatively long ranges.

Single Action:

In revolvers, any gun whose hammer must be manually cocked for each shot. In semi-automatic pistols, any pistol where the hammer or striker must be manually cocked before the first shot can be fired. (Cf. DOUBLE ACTION)


A target shooter's term for light, target loads for the .45 ACP. (Cf. HARDBALL)

Specialty Pistol:

A large, long-barreled pistol, nearly always a single-shot, capable of chambering cartridges hitherto appropriate only for rifles. Usually intended for hangun hunting or metallic silhouette shooting.


An axially mounted, spring-propelled firing pin.


The practice of polishing, enlarging and recontouring the feed ramp of an auto pistol's barrel to ensure more reliable functioning, especially with semi-wadcutter and other non-standard bullets.


Stands for Total Metal Jacketed, a term used by Speer to describe the full-metal-jacketed bullets in which even the base is jacketed.

transfer Bar:

A revolver safety mechanism that delivers the force of the hammer blow to the firing pin by means of an intermediary piece of metal that rises into firing position only when the trigger is pulled.

Trigger Job:

A process of lightening and otherwise improving trigger pull by means of polishing and reshaping the engagement surfaces. Can be dangerous unless performed by a qualified gunsmith.

Wadcutter (WC):

A flat-ended, nearly cylindrical bullet designed for cutting full-caliber holes in targets. Especially favored in light, target loads.


A term coined by gunwriter Robert T. Shimek to denote the modern breed of 9mm Parabellum auto pistols of recent design, usually featuring high magazine capacity and a double-action trigger mechanism or other modern ignition system (e.g., the squeeze-cocker of the Heckler & Kock P7 series or the Safe Action of the Glock).

This information is from the 1994 issue of Handguns Annual Magazine

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Most recent revision July 1999