Long gun term. Some long guns feature a standard stock (one which can be braced against the shoulder), but which includes an extra handle behind the trigger for the firing hand to wrap around. The extra handle is called a pistol grip. When used properly by an experienced shooter, such a pistol grip can improve the controllability of the gun, though the tradeoff is that firing it can be uncomfortable for the wrist. Take a regular long gun, usually a shotgun. Get rid of the standard stock so that the shooter is no longer able to brace the firearm against a shoulder while firing it. Equip it with a super-short, pistol-shaped stock instead, so that the gun is most easily fired from the hip. This looks cool, but is often painful to fire and is no aid to accuracy. When combined with other features such as an Adjustable Stock Flash Reducer, and/or the ability to hold over five rounds, a gun equipped with either type of pistol grip becomes an "assault weapon" and is subject to additional regulation or outright prohibition in many states. None of these devices alter the gun's basic firing mechanism or its force in any way.
The shape given to the small of the stock of a shoulder arm to afford a better grasping surface for the hand. A full pistol grip curves sharply downward from the stock, bending close behind the trigger guard. A half pistol grip or semi-pistol grip slants only slightly downward as a protuberance from the small of the stock.
The handle of a handgun or protrusion on the buttstock or fore-end of a shoulder-operated gun that resembles the grip or handle of a handgun. A "semi-pistol grip" is one less pronounced than normal; a "vertical pistol grip" is more pronounced than normal.