ammo vs implements of war

ammo and implements of war both are nouns.

Word	Noun	Adjective	Verb	Adverb
ammo	Yes	No	No	No
implements of war	Yes	No	No	No

As nouns, implements of war is a hypernym of ammo; that is, implements of war is a word with a broader meaning than ammo:

Other hypernyms of ammo include arms, munition, weaponry, weapons system.

ammo (noun)	implements of war (noun)
projectiles to be fired from a gun	weapons considered collectively