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Glossary Results

D - 46 matching terms

DAMASCUS BARREL
See Barrel, Damascus.

DATUM
A reference plane, point or diameter that provides a base for calculations and measurements.

DECAPPER
A tool used to remove primers from cartridge cases or shells.

DEFLAGRATION
A rapid combustion reaction which is propagated at a sub-sonic rate by heat transfer into the reacting material. This reaction is accompanied by a vigorous evolution of heat and flame. The flow of reaction products is in the direction opposite that of the combustion propagation (unlike DETONATION). Deflagration is usually dependent upon having fuel and oxidizing agent in very close contact, either from having the fuel as a finely divided mixture with the oxidant, or by combining the two in the same chemical compound or mixture. Deflagration exhibits a dependence upon the surrounding gas pressure.

DEFLECTION
The variation in the normal flight path of a projectile caused by wind or other external influences.

DEFLECTOR
A device mounted on the receiver or frame of a firearm to change the direction of fired-case ejection.

DELAYED FIRE
Any delay in firing of an abnormal duration. This implies that firing does eventually occur.

DEMI-BLOCK
A type of double barrel construction in which the two barrels are fastened together by a dovetail arrangement.

DENT REMOVER
A gunsmithing tool used to remove dents from shotgun barrels. Also called Dent Raiser.

DERRINGER
A generic term applied to many variations of small one-or two-shot pistols, using both percussion caps and cartridges. The original designer, Henry Deringer, spelled his name Deringer, not Derringer.

DETENT
Indentation used as a stop for a spring-load lock.

DETONATION
An extremely rapid exothermic decomposition reaction which proceeds at a rate greater than the speed of sound within the reacting material (unlike DEFLAGRATION). The normal mode of initiation is shock (such as a blasting cap or high level mechanical shock), or from initial combustion which, due to peculiarities of confinement or other circumstances accelerates to such a degree that a shock wave is formed. Behind the shock wave is a reaction zone where material is converted to gaseous products at high temperature and pressure. The flow of the reaction is in the same direction as the propagation.

DEWAT
An acronym for DEactivated WAr Trophy.

DISASSEMBLY
To take apart a firearm.

DISC, PAPER
Small circular piece of treated paper cut and pressed into the primer cup in contact with the priming mixture. Also called Foil.

DISCHARGE
To cause a firearm to fire.

DISCONNECTOR
A device intended to disengage the sear from the trigger. 1.) In a manually operated firearm, it is intended to prevent firing without pulling the trigger. 2.) In a semiautomatic firearm, it is intended to prevent full automatic firing.

DISJUNCTOR
An electronic pulse forming device used in measuring projectile velocities.

DISPERSION, HORIZONTAL
The greatest horizontal distance between any two bullet holes on a target, normally measured center to center.

DISPERSION, VERTICAL
The greatest vertical distance between any two bullet holes on a target, normally measured center to center.

DOG, CARRIER
A repeating action firearm component which engages or is attached to the carrier or lifter and acts to control its motion. Sometimes called Lifter Pawl.

DOLL’S HEAD
A usually round extension at the top of the barrel or rib of a shotgun which fits into a matching hole in the top of the standing breech.

DOUBLE ACTION
See Action, Double.

DOUBLE BASE POWDER
See Powder, Double Base.

DOUBLE SET TRIGGER
See Trigger, Double Set.

DOUBLE-BARREL
Two barrels in a firearm mounted to one frame. Can be vertically (“over-under”)or horizontally (“side-by-side”) aligned.

DOUBLE-GUN
A two-barrel firearm, usually side by side. Also known as Double Barrel or Double. See Shotgun, Double.

DOUBLING
Unintentional firing of a second shot.

DOUGHNUT PATTERN
See Pattern, Doughnut.

DRAM EQUIVALENT
The accepted method of correlating relative velocities of shotshells loaded with smokeless propellant to shotshells loaded with black powder. The reference black powder load chosen was a 3 dram charge of black powder, with 1 1/8 oz. of shot and a velocity of 1200 fps. Therefore, a 3 dram equivalent load using smokeless powder would be with 1 1/8 oz. of shot having a velocity of 1200 fps. or 1 1/4 oz. of shot and a velocity of 1165 fps. A 3 1/4 dram equivalent load might have 1 1/8 oz. of shot and a velocity of 1255 fps. Abbreviated Dram Equiv.

DRAW MARK
1. Ammunition - a longitudinal scratch on a cartridge case caused by foreign material on either the draw punch or die during fabrication.
2. Arms - See Witness Mark.

DRIFT
The deviation in flight of a bullet from the center line of the bore due to the gyrational spin of bullet imparted by the rifling.

DRILLING
A three-barreled long gun in which a combination of smoothbore and rifled barrels is used.

DROP
See Stock Dimensions.

DROP AT COMB
See Stock Dimensions.

DROP AT HEEL
See Stock Dimensions.

DROP AT MONTE CARLO
See Stock Dimensions.

DROP BLOCK ACTION
See Action, Dropping Block.

DROP SHOT
See Shot, Drop.

DROP TEST, PRIMER
See Sensitivity Test for Primed Shells or Primers.

DROP, BULLET
The vertical distance a bullet has fallen, under the influence of gravity, at any point in its flight path. The distance is measured from a point on its path to the straight line from axis of the bore to target.

DRY FIRING
The releasing of the firing-pin on an unloaded chamber of a firearm.

DUMMY SCREW
See Plug, Screw.

DUPLEX LOAD
See Load, Duplex.

DUST COVER
A cover over the ejection port of a firearm to reduce the possibility of the entrance of foreign matter into the action.

DUST SHOT
See Shot, Dust.

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Abbreviations:

A-L | M-Z