gunnery vs weapons system

gunnery and weapons system both are nouns.

Word	Noun	Adjective	Verb	Adverb
gunnery	Yes	No	No	No
weapons system	Yes	No	No	No

As nouns, weapons system is a hypernym of gunnery; that is, weapons system is a word with a broader meaning than gunnery:

Other hypernyms of gunnery include arms, implements of war, munition, weaponry.

gunnery (noun)	weapons system (noun)
guns collectively	weapons considered collectively