Letter A

The Definition of Action

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Action

The working mechanism of a firearm involved with presenting the cartridge for firing, and in removing the spent casing and introducing a fresh cartridge. For example some of the most common types of Actions are single, double, bolt, lever and pump.


19 Other Firearms Definitions You Need To Know


Weaver Stance

In the Weaver stance, the body is bladed partly sideways in relation to the target rather than squared towards it (think boxing or martial arts fighter stance). The elbows are flexed and pointed downward. The strong-side arm is slightly straighter than the weak-side arm. Even though the legs are not square to tharget, the hips should be square to the target. The feet should be pointed at the target. The shooter pushes out with the gun hand, while the weak hand pulls back. This produces a push-pull tension which is the chief defining characteristic of the Weaver stance.

Recoil Operation

Recoil operation is an operating mechanism used in locked-breech, autoloading firearms. As the name implies, these actions use the force of recoil to provide energy to cycle the action.

Intercepting Sear

A second sear, poised just behind a second notch in the hammer. It is possible that when a cocked firearm is dropped or sharply jarred, a single sear could jump out of its notch and the hammer could fall, firing the gun accidentally. In this event, an intercepting sear would engage before the hammer could fall completely, preventing an accidental discharge. On a gun with intercepting sears, only by pulling the trigger are both sears moved out of the way simultaneously, allowing the gun to fire. Intercepting sears are usually found on better sidelock actions. They are sometimes found on best boxlocks, and can be recognized by an extra screw behind the action fences, in addition to the usual two screws (or pins) along the lower rear of the receiver.

Pigeon Gun

A double-barrel shotgun, with relatively tight choke boring and a relatively high-combed stock used for shooting live pigeons (euphemistically known as flyers) which normally rise when released. To better absorb recoil, a pigeon gun is normally heavier than a field gun as one shoots heavy loads and walks only a little. Because of the inevitable expense of this shooting discipline, pigeon guns are often built to a high standard of quality and reliability in deluxe grades with highly figured walnut stocks and fine engraving.

High-Capacity Magazine

An inexact, non-technical term indicating a magazine holding more rounds than might be considered "average.".

Crane

A swing-out arm on a revolver, to which the cylinder is mounted when opened facilitates loading and cleaning.

Red Dot Sight

A type of reflector (reflex) sight for firearms that gives the uses a red light-emitting diode as a reticle to create an aimpoint.

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.

Yaw

The heading of a bullet, used in external ballistics that refers to how the Magnus effect causes bullets to move out of a straight line based on their spin.

Powder Charge

The amount of propellant powder that is suitable for specific cartridge-bullet combination, or in the case of shotshells, for a specific weight of shot and wad column.

Receiver Ring

The portion of the receiver which is threaded so the barrel can be attached to it.

Open Bolt

A type of firearm in which the action is in the open position and the chamber empty prior to firing. When the trigger is pressed the bolt moves forward, chambering a cartridge and firing it and returning to the open position. When firing is stopped the bolt remains open and the chamber empty.

Thunder

With the execption of the BP model series, Thunder is the name of all of Bersa's pistols. The line currently consists of three frames.

• The Thunder .380 series, which is a very reliable and good looking compact blowback system .380 acp pistol (there is also a .22lr version).
• The full size Thunder Pro series (avalable in 9mm and .40 S&W) is a locked breech design.
• The Thunder Ultra Compact Pro series, locked breech, short recoil design which is more of a commander size Thunder Pro (available in 9mm, .40 S&W, and .45 acp).
The Bersa Thunders are well known among firearms enthusiasts for being extremely high quality guns at reasonable prices.

Caliber

The diameter of the bore of a firearm measured as a fraction of an inch. Although such a measurement may be frequently stated in millimeters. It is correctly expressed as ".40 caliber" (note the decimal point) or as "10 millimeter" (without "caliber" or the leading decimal point). Caliber numbers when used to identify the size of the bullet a gun will file are usually followed by words or letters to create the complete name of the cartridge. These letters often represent a brand name or an abbreviation for the name of the company that first introduced the round.

Reset Point

The point of the trigger's return at which the gun's internal mechanisms are ready to fire another round.

Breech Pressure

The amount of rearward force exerted by the propellant gases on the bolt or breech of a firearm action or breech when a projectile is fired. The applied force has both magnitude and direction, making it a vector quantity. This is also known as Bolt Thrust on firearms that are Bolt Action

Trigger Break

The point at which the trigger allows the hammer to fall, or releases the striker, so that the shot fires. The ideal trigger break is sudden and definite. "Like a glass rod" is the cliche term shooters use to describe the ideal crisp, clean break.