pistol vs shooting iron

pistol and shooting iron both are nouns.

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

As nouns, pistol and shooting iron are synonyms defined as:

pistol and shooting iron: a firearm that is held and fired with one hand

Other synonyms of pistol include handgun, side arm.

pistol (noun)	shooting iron (noun)
a firearm that is held and fired with one hand	a firearm that is held and fired with one hand