assault gun vs armored vehicle

assault gun and armored vehicle both are nouns.

Word	Noun	Adjective	Verb	Adverb
assault gun	Yes	No	No	No
armored vehicle	Yes	No	No	No

As nouns, armored vehicle is a hypernym of assault gun; that is, armored vehicle is a word with a broader meaning than assault gun:

assault gun: an armored vehicle with the chassis of a tank (but no turret) and a large gun; used as an antitank weapon and to support infantry
armored vehicle: a vehicle that is protected by armor plate

Other hypernyms of assault gun include armoured vehicle.

assault gun (noun)	armored vehicle (noun)
an armored vehicle with the chassis of a tank (but no turret) and a large gun; used as an antitank weapon and to support infantry	a vehicle that is protected by armor plate
any of the automatic rifles or semiautomatic rifles with large magazines designed for military use