Gunstock and Pistol grip

Gunstock noun - The handle of a handgun or the butt end of a rifle or shotgun or part of the support of a machine gun or artillery gun.

Pistol grip and gunstock are semantically related. In some cases you can replace phrase "Pistol grip" with "Gunstock", this terms are similar.

Pistol grip noun - A handle (as of a gun or saw) shaped like the butt of a pistol.

Gunstock and pistol grip are semantically related. Sometimes you can use "Gunstock" instead a noun phrase "Pistol grip".