ammunition vs arms

ammunition and arms both are nouns.

Word	Noun	Adjective	Verb	Adverb
ammunition	Yes	No	No	No
arms	Yes	No	No	No

As nouns, arms is a hypernym of ammunition; that is, arms is a word with a broader meaning than ammunition:

Other hypernyms of ammunition include implements of war, munition, weaponry, weapons system.

ammunition (noun)	arms (noun)
projectiles to be fired from a gun	weapons considered collectively
information that can be used to attack or defend a claim or argument or viewpoint	the official symbols of a family, state, etc.
any nuclear or chemical or biological material that can be used as a weapon of mass destruction