Wildcat Cartridge

A wildcat cartridge, or wildcat, is a custom cartridge for which ammunition and/or firearms are not mass-produced. These cartridges are often created in order to optimize a certain performance characteristic (such as the power, size or efficiency) of an existing commercial cartridge. Developing and using wildcat cartridges does not generally serve a purpose in military or law enforcement; it is more a hobby for serious shooting, hunting, gunsmithing and handloading enthusiasts, particularly in the United States. There are potentially endless amounts of different kinds of wildcat cartridges: one source of gunsmithing equipment has a library of over 6,000 different wildcat cartridges for which they produce equipment such as chamber reamers.

Rimless

A cartridge in which the base diameter is the same as the body diameter. The casing will normally have an extraction groove machined around it near the base, creating a "rim" at the base that is the same diameter as the body diameter.

Magazine Safety

A mechanism that prevents the gun from being able to fire when the magazine is removed from the gun, even if there is still a round in the chamber.

Sight Radius

The distance between the rear sight and the front sight. As a longer lever provides greater mechanical advantage, the greater the distance between the two sights, the more inherently accurate they will be.

Firepower

A volume of fire delivered by a military unit. Incorrectly used by the media to mean the ability of a small arm to be discharged many times without reloading.

Corto

Italian for "short." Seen as part of a cartridge designation. On some Italian manufactured guns that use .380 ACP, the designated caliber is 9mm Corto (9mm Short), which is also the same as the German 9mm Kurtz

Heel & Toe Plates

Protective plates, usually of steel or horn, covering the top and bottom of a gunstock's butt only (the heel and the toe); leaving wood exposed in the center

Capper

A hand tool used in the field for inserting live and removing spent primers from cartridges.

Igniting Charge

The charge used to ignite the propelling charge.

Bore

The tunnel down the barrel of a firearm through which the projectiles travel.

• A smooth-bore firearm is one that does not have rifling on the barrel's internal surface.
• A big-bore firearm is one that fires a large caliber.
• A small-bore firearm is one that fires a small caliber.

Quaker Gun

Not really a gun at all. During the U.S. Civil War, both sides would take tree branches or tree trunks, paint them black, and position them so that they appeared to be rifles or artillery pieces. By doing so, they could fool the other side into believing that they had more artillery than they really did.

Gunpowder

Also called black powder, gunpowder is a mixture of sulfur, charcoal, and potassium nitrate. It burns rapidly, producing a volume of hot gas made up of carbon dioxide, water, and nitrogen, and a solid residue of potassium sulfide. Because of its burning properties and the amount of heat and gas volume that it generates, gunpowder has been widely used as a propellant in firearms and as a pyrotechnic composition in fireworks. The term gunpowder also refers broadly to any propellant powder. Modern firearms do not use the traditional gunpowder (black powder) described here, but instead use smokeless powder.

Mirage

A tendency for layers of air of different temperatures near the warm ground to cause refraction in the line of sight and disturbance of the perceived point of aim.

Grip Safety

A passive, external safety typically located on the backstrap, which must be fully depressed to release the trigger. Most 1911-pattern pistols feature a grip safety.

Hardball

Slang for a full metal jacket bullet with a round nose. The term is most commonly used in referring to .45 ACP caliber ammunition, but may be used for other calibers as well.

Underwater Firearm

A firearm specially designed for use underwater.

M1911

The official US military designation for the Colt .45 semiautomatic pistol adopted by the US in 1911. The gun was designed by John Moses Browning, and produced by Colt. During trials, the Browning-Colt design beat out several competing designs, including one from Savage and a .45 caliber version of the German Parabellum ("Luger"). The M1911 saw its first combat in the Philippines and then in World War I. Early use showed that it could be improved and in 1921 the M1911A1 was introduced, which featured a few changes like a reocontoured frame, shorter trigger, and a rounded backstrap. The M1911A1 remained the standard US military handgun until it was replaced in the 1980's by the Beretta M9. However, it remains very popular with civilian shooters in the US, and has been modified extensively to update it to conform to more modern theories of handgun usage.

Zero

A firearm is said to be "zeroed in" when its sights have been adjusted so that the bullet will hit the center of the target when the sights are properly aligned upon the center of the target. The farthest distance from a firearm at which the bullet's path and the point of aim coincide. This term is also used to mean the process of insuring that the sights of a firearm are properly aligned so that where they indicate the bullet will strike is in fact where it strikes.

Necking Down

Shrinking the neck of an existing cartridge to make it use a bullet of a different caliber. A typical process used in the creation of wildcat cartridges.

Stock

The back part of a rifle or shotgun, excluding the receiver.