heavy weapon vs gunstock

heavy weapon and gunstock both are nouns.

Word	Noun	Adjective	Verb	Adverb
heavy weapon	Yes	No	No	No
gunstock	Yes	No	No	No

heavy weapon (noun)	gunstock (noun)
large but transportable armament	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