Hadden rifling
A type of rifling characterised by wide shallow grooves.
Hagbut, Hackbutt, Haquebut, Hacke
A 16th century harquebus under 27 inches overall and with a butt bent or hooked to facilitate holding.
Hair trigger see Trigger
Half bent
The first or half cock notch in the tumbler of a gunlock.
Half cock see Cock
Half pistol grip see Pistol grip
Hammer
On a flintlock it was the piece hit by the flint but in subsequent locks it was the striking piece, corresponding to a flintlocks cock. In modern usage a hammer denotes a pivoted mechanism, that moves about an axis to deliver its impulse to the firing pin. A hammer may be visible or contained within the guns frame (hammerless). Its action may carry the firing pin directly into contact with the primer, or it may impel a separate firing pin forward against the primer. A burr hammer denotes an exposed hammer with a serrated gripping surface. A spur hammer denotes any hammer having a protruding cocking spur. A straight line hammer is found on certain guns like the Smith and Wesson Straightline in which the hammer drives straight forward when released from the cocked position. On a revolver the hammer is usually exposed for cocking, though on some pocket models the spur is omitted.
Hammerless
1 Loosely referring to any firearm in which the hammer or striker is concealed within the frame.
2 Technically it refers to any firearm employing a striker rather than a hammer. In this sense a weapon with a concealed hammer is not a hammerless weapon.
Hand cannon
Any of a variety of small crude cannon dating from the early 15th century and addapted for individual use by fitting wooden stocks to rest against the shooters chest, arm or shoulder. The hand cannon was the prototype of all subsequent shoulder arms.
Hand firearm
Any firearm fired from one hand.
Handguard
A wood or ventilated metal portion of the stock covering a part of the barrel forward of the receiver and designed to protect the hand from burns when the barrel becomes heated by rapid firing. Fitted to most military arms but rarely found on sporting weapons.
Hand gun
1 A hand cannon, it had a straight handle and was often hung from the neck by a cord. The term was applied to all small guns of the 15th and 16th centuries to distinguish them from cannon.
2 A pistol or revolver.
Hang fire
A delay in firing or a failure to fire, a delayed ignition of the powder charge after the hammer or striker has been released. Very dangerous as there may be several seconds between when the firing pin strikes the primer and when the weapon discharges.
Harmonica repeater
Any firearm fed by a cartridge block either down, up or across the breech
Harquebus, Arquebus
Originally a smoothbore matchlock introduced in Germany in the mid 15th century. In some details it resembled the crossbow which it superseded. The term harquebus which means "gun with a hook" persisted through wheellock and flintlock designs, coming in time to denote a gun of fine workmanship as distinguished from the musquet or common military arm. By the late 16th century the name harquebus had been superseded as a descriptive term by musket.
Headspace
1 On a machinegun the adjustable space between the bolts forward end and the rear end of the barrel.
2 The distance between the case head and the bolts face when the firearms action is locked. In the chamber of a gun using rimmed cartridges headspace is measured from the breechblocks face to the point at the chambers rear that supports the forward surface of the case rim. In the chamber of a gun using rimless necked cartridges headspace is measured from the breechblock or bolts face to some predetermined point on the chambers shoulder. In the chamber of a gun using rimless straight bodied cartridges headspace is measured from the breechblocks face to the squared shoulder of the chamber just behind the throat.
Heel
The upper rear corner of the butt.
Highlander pistol
An all steel pistol developed from the German wheellock and first used in Scotland in 1598.
Hinged frame action see Action, hinged frame
Hollow point see Bullet, hollow point
Holster
A leather or web carrying case for a revolver or pistol, usually conforming to the weapon’s shape and attached to a belt or a saddle.
Hooded sight see Sight
Horse pistol
Any of a variety of large pistols formerly carried by horsemen.
Howitzer
Short barrelled artillery weapon projecting heavy missiles in a high trajectory.