gun turret vs weapons platform

gun turret and weapons platform both are nouns.

Word	Noun	Adjective	Verb	Adverb
gun turret	Yes	No	No	No
weapons platform	Yes	No	No	No

As nouns, weapons platform is a hypernym of gun turret; that is, weapons platform is a word with a broader meaning than gun turret:

gun turret: a self-contained weapons platform housing guns and capable of rotation
weapons platform: any military structure or vehicle bearing weapons

Other hypernyms of gun turret include platform.

gun turret (noun)	weapons platform (noun)
a self-contained weapons platform housing guns and capable of rotation	any military structure or vehicle bearing weapons