peacekeeper vs shooting iron

peacekeeper and shooting iron both are nouns.

Word	Noun	Adjective	Verb	Adverb
peacekeeper	Yes	No	No	No
shooting iron	Yes	No	No	No

As nouns, shooting iron is a hypernym of peacekeeper; that is, shooting iron is a word with a broader meaning than peacekeeper:

Other hypernyms of peacekeeper include handgun, pistol, side arm.

peacekeeper (noun)	shooting iron (noun)
the pistol of a law officer in the old West	a firearm that is held and fired with one hand
someone who keeps peace
a member of a military force that is assigned (often with international sanction) to preserve peace in a trouble area