Glossary of Firearms Terms - D

D

• damascus barrel or damascus twist: An obsolete method of manufacturing a firearm barrel made by twisting strips of metal around a mandrel and forge welding it into shape. See also Damascus steel.

• direct impingement: A type of gas operation for a firearm that directs gas from a fired cartridge directly to the bolt carrier or slide assembly to cycle the action.

• doglock: The lock that preceded the 'true' flintlock in both rifles and pistols in the 17th century. Commonly used throughout Europe in the 1600s, it gained popular favor in the British and Dutch military. A doglock carbine was the principal weapon of the harquebusier, the most numerous type of cavalry in the armies of Thirty Years War and the English Civil War era.

• double-barreled shotgun: A shotgun with two barrels, usually of the same gauge or bore. The two types of double-barreled shotguns are over/under (abbreviated as O/U), in which the two barrels are stacked on top of each other, and side-by-side (abbreviated as SxS), in which the two barrels sit beside each other. See photo at right for example of side-by-side double-barreled shotgun. For double-barreled guns that use one shotgun barrel and one rifle barrel, see combination gun.

• double rifle: A rifle that has two barrels, usually of the same caliber. The two types of double rifles are over/under (abbreviated as O/U), in which the two barrels are stacked on top of each other, and side-by-side (abbreviated as SxS), in which the two barrels sit beside each other. The photo at right is of a side-by-side shotgun, but a side-by-side rifle is very similar. For double-barreled guns that use one shotgun barrel and one rifle barrel, see combination gun.

• drilling: a firearm with three barrels (from the German word drei for three). Typically it has two barrels side by side on the top, with a third rifle barrel underneath. This provides a very versatile firearm capable of taking winged animals as well as big game. It also is useful in jurisdictions where a person is only allowed to own a single firearm.

• drum magazine: a type of firearms magazine that is cylindrical in shape, similar to a drum.

• dry fire: the practice of "firing" a firearm without ammunition. That is, to pull the trigger and allow the hammer or striker to drop on an empty chamber.

• 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.

• dummy: A round of ammunition that is completely inert, i.e., contains no primer, propellant, or explosive charge. It is used to check weapon function, and for crew training. Unlike a blank it contains no charge at all.