Letter H

The Definition of Hammer Spur

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Hammer Spur

The thumb-piece on the top rear of the hammer that enables it to be manually drawn back to full cock.


19 Other Firearms Definitions You Need To Know


Telescopic Sight

An optical sight, offering some magnification, often variable, with some kind of adjustable aiming grid inside (a reticle), which when mounted on a firearm, usually a rifle, makes sighting easier.

Revolver

A repeating firearm in which the ammunition is held in a multi-chambered cylinder, which is rotated to bring each chamber in line with the barrel. Most revolvers are handguns, although shoulder-fired arms have been made using this sort of mechanism.

Holster

A gun holder that may be strapped to a human body, or affixed to the inside of a pack or bag, or dropped into a pocket. A holster serves to protect the gun's mechanisms and finish, to provide security by covering the trigger so it cannot be pulled inadvertently, and to present the grip of the gun at a constant angle for easy access. Some holsters also serve to obscure the outline of the gun so it may be more easily concealed. Typically made from leather or in plastic.

Percussion Cap

A small metal explosive-filled cup which is placed over the nipple of a percussion firearm. As the cap is struck by the hammer, it explodes and sends a flame through the flashhole in the nipple to the main powder charge.

Combination Gun

A shoulder-held firearm that has two barrels; one rifle barrel and one shotgun barrel. Most combination guns are of an over/under design (abbreviated as O/U), in which the two barrels are stacked vertically on top of each other, but some combination guns are of a side-by-side design (abbreviated as SxS), in which the two barrels sit beside each other.

Selective-Fire

A firearm's ability to be fired fully automatically, semi-automatically or, in some cases, in burst-fire mode at the option of the firer.

Self-Opening

Attribute of a break-open gun whereby the barrels drop down simply by pressing the toplever without muscling them open manually. The Holland & Holland system utilizes a coil spring within a cylindrical housing mounted just ahead of the forward lump to urge the barrels open. The Purdey system utilizes residual energy remaining in the mainspring after the gun has been fired. Both systems enable a shooter to load more quickly when birds are coming fast.

Bayonet Lug

A mounting point on a small arm that allows a bayonet or other accessory to be attached.

Delayed Blowback

A self-loading firearm whose breechblock and barrel are not positively locked together, but which incorporates a mechanism which initially restricts the breechblock from moving when fired, delaying its opening.

Magazine Disconnect

Another term for Magazine Safety

Ballistics

The science of cartridge discharge and the bullet's flight. Internal ballistics deals with what happens inside of a firearm upon discharge. External ballistics is the study of a projectile's flight, and terminal ballistics is the study of the impact of a projectile.

Monoblock Barrels

A method of building a pair of barrels where the entire breech end of both barrels and the lumps together are machined from one solid piece of steel. The barrel tubes are then fitted separately into this monoblock and the ribs attached. Often identifiable by a distinctive ring around the barrels about three inches in front of the breech end. The favored jointing method of the Beretta company. An incorrect euphemism for sleeved barrels.

Back Bored

A shotgun barrel that has a bore diameter increased beyond standard specifications, but less than the SAAMI maximum. Done in an attempt to reduce felt recoil, improve patterning, or change the balance of the shotgun.

Shoulder

To bring the butt of a long gun's stock to the shooter's shoulder, preparatory to firing the gun.

Reset Point

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

Tunnel Claw Mount

A claw [scope] mount with openings through which a shooter can use a rifle's iron sights without removing the scope.

Adjustable Trigger

A trigger that can be easily adjusted by the user. Adjustable triggers are common on specialized target-shooting firearms.

Doll's Head

A rib extension on a break-open gun, ending in a circular or semi-circular shape in plan (resembling the head of a doll), mating into a similarly-shaped recess in the top of the receiver, designed to resist the tendency of the barrels to pull away from the standing breech when firing. Because an action's centerpoint of flexing when firing is at the base of the standing breech, not at the hingepin, a passive doll's head extension makes an effective extra fastener, even without additional mechanical locks operated by the opening lever.

Full Stock

A rifle or carbine with a one-piece stock extending to the muzzle. Sometimes called a Mannlicher stock, although such a term is confusing because Mannlicher Schoenauer rifles are built with both full and half stocks. Traditional in Europe for close-range woodland hunting, but not noted for extreme, long-range accuracy.