Letter D

The Definition of Dum-Dum

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Dum-Dum

A bullet designed to expand on impact, increasing in diameter to limit penetration and/or produce a larger diameter wound. The two typical designs are the hollow point bullet and the soft point bullet. Expanding bullets were given the name Dum-dum, or dumdum, after an early British example produced in the Dum Dum Arsenal, near Calcutta, India by Captain Neville Bertie-Clay in the the mid-1870s. Modern sef-defensive, JHP (Jacketed Hollow Point), ammunition are based on the original dum-dum ammunition design and principles.


19 Other Firearms Definitions You Need To Know


Igniting Charge

The charge used to ignite the propelling charge.

Sabot

An oversized, lightweight housing that allows a sub-calibre projectile to be fired in a larger-diameter bore, usually in the interest of increased velocity. The sabot falls away from the actual projectile upon exiting the muzzle. For example, a hunter could use his .30-30 deer rifle to shoot small game with .22 centerfire bullets.

Mouse Gun

A name for any palm sized handgun which fires a small caliber.

SMLE

Abbreviation for Short Magazine Lee Enfield. The standard British Army rifle from around 1895 to 1957.

Co-Witness Sighting

Co-Witness Sighting is the use of any iron sight mounted onto a rifle that is fitted with an optical sight as a primary sighting system. They come in two basic configurations, fixed or flip-up. The idea is that if you align your red dot and your iron sights you have a backup aiming system on the gun.

Group

A set of holes in a target left by a succession of bullets fired from the same rifle or handgun, using the same ammunition and sight setting. Fired (within the limits of one's marksmanship ability) to determine the inherent accuracy of the rifle/ammunition combination, and to aid in the proper adjustment of the sights.

Double Rifle

Two independent rifles, built on one frame, designed to allow two virtually instantaneously quick, totally reliable shots. The barrels may be arranged either side-by-side or over-and-under. The apogee of the gunmaker's art. Particularly useful against dangerous game, which may be moving, and in your direction, with vengeance on its mind.

Trigger Jerk

Yanking the trigger back abruptly, thus pulling the muzzle of the gun downward at the moment the shot fires.

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.

Brick

A box of ammunition roughly equal in size and weight to a brick. Most often used to describe a 500-round container of .22 Long Rifle ammunition.

Antique Firearm

Defined according to Section 921 (a) (16), Title 18, U.S.C. as:

A. any firearm (including any firearm with matchlock, flintlock, percussion cap, or similar type of ignition system) manufactured in or before 1898; and
B. any replica of any firearm described in subparagraph (A) if such replica (i) is not designed or redesigned for using rimfire or conventional centerfire fixed ammunition, or (ii) uses rimfire or conventional centerfire fixed ammunition which is no longer manufactured in the United States and which is not readily available in the ordinary channels of commercial trade.

Hot Range

A condition (status) of a shooting range that shooters may commence to fire.

Gas Check

A metal cup placed on the end of a lead bullet to protect the lead against the hot gases of the burning powder charge. Used in some types of firearms ammunition when non-jacketed bullets are used in high pressure cartridges, to prevent the buildup of lead in the barrel and aid in accuracy.

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.

Biathlon

A shooting sport that combines both skiing and rifle shooting. It is the only shooting activity in the Winter Olympics. There is also a summer biathlon which involves running and shooting but it is not yet an Olympic event.

Stripper Clip

Simple clips made of metal or sometimes plastic that hold several rounds of ammunition in a row and is used to quickly fill a magazine.

Charging Handle

A device on a firearm which, when operated, results in the hammer or striker being cocked or moved to the ready position.

Breech

The rear end of the barrel into which the cartridge is inserted

Monte Carlo Comb

The Monte Carlo comb came to rifles via shotgun stocks. It rises well above the ordinary comb line of the stock at the butt and tapers downward toward the point of the comb. This raised portion of the stock lifts the face of the shooter and his or her line of sight well above the standard elevation provided by the classic style. However, the same amount of drop is maintained at the buttstock. A shooter with a long neck who often has trouble getting his or her face down far enough on the comb of the regular stock benefits from the Monte Carlo style.