Letter L

The Definition of Lock Time

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Lock Time

The interval of time between trigger release and the detonation of the primer. Generally, the faster the lock time the better, because this makes it easier to shoot accurately.


19 Other Firearms Definitions You Need To Know


Pellet (shotgun)

Small spherical projectiles loaded in shotshells and more often called "shot."

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.

Island Rear Sight

A rear barrel sight base, more articulated than having the sight simply dovetailed into the barrel, but not requiring as much gunsmithing as having it mounted onto a proper quarter-rib.

Toplever

A lever on a break-open gun mounted to the top of the receiver which, when pushed with the thumb (normally) to the right, operates (usually) a Scott Spindle, which in turn withdraws (usually) a Purdey Underbolt from the bites in the lumps of the barrels, allowing them to hinge downwards and the gun to open.

Straddle Floorplate

A hinged plate covering the bottom of a rifle magazine and extending rearward on either side of the triggerguard. This design allows it to be more securely fastened for one more imperceptible step towards total reliability.

Chain Gun

A type of machine gun or autocannon that uses an external source of power to cycle the firearm.

Cast On

An offset of a gun stock to the left, so that the line of sight aligns comfortably with the left eye while the butt of the stock rests comfortably on the left shoulder. Almost all left-handed shooters benefit from a little caston and most custom built guns are made this way. The only question is how much. The caston of a gun is about right when, with the gun comfortably mounted, the front bead lines up with the center of the standing breech.
A stock offset to the right, for shooting from the right shoulder is said to be

Beavertail

A large piece of curved metal at the top of the grip on a pistol which protects the user's hand from getting "bitten" by the hammer or slide. It is nearly always the top part of the grip safety commonly found on many 1911-style pistols.

Bore Snake

A bore snake is a tool used to clean the inside (bore) of the barrel of a gun. It resembles a short section of rope with a smaller, weighted cord attached to one end to help feed the bore snake through the barrel. A bore snake often has one or more integrated brushes to help clean the barrel, and may also be used to apply lubricant. It is an alternative to using a cleaning rod and patches to clean the barrel of a gun. Bore snakes are made in different sizes for different calibers and gauges of guns.

Grain

A unit of weight widely used to express the weight of bullets and of powder charges. Equal to 1/7000 pound.

Polygonal Rifling

A type of gun barrel rifling where the traditional lands and grooves are replaced by "hills and valleys" in a rounded polygonal pattern, usually a hexagon or octagon. Polygons with a larger number of edges provide a better gas seal in relatively large diameter polygonally rifled bores.

Bottlenecked (Bottle Necked)

A type of cartridge whose bullet diameter is substantially less than the body diameter of the casing.

Forend

One of the three major dismountable components of a break-open gun (the others being the barrel(s) and the action/buttstock) which secures the barrels to the receiver, often houses the ejector mechanism, and for some, provides a handle for the one's secondary hand.

Squib

An underpowered powder charge, usually caused by a fault in cartridge loading, often insufficient to expel a projectile from the muzzle of a firearm. If such a blockage is not cleared, the next attempted shot could cause the barrel at least to bulge, and very possibly to burst.

Port

An opening. The ejection port is the opening in the side of a semi-auto from which spent cases are ejected.

Recoil Lug

A stout flange, invariably incorporated into the underside of the front receiver ring of a bolt action, and also frequently incorporated into the underside of the barrel of a heavily-recoiling rifle, which when properly bedded, transfers recoil to the stock.

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

Chamber

The rear portion of the barrel or firing cylinder in which the cartridge is inserted prior to being fired. Rifles and pistols generally have a single chamber in their barrels, while revolvers have multiple chambers in their cylinders and no chamber in their barrel.

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.