handgun vs shooting iron

handgun and shooting iron both are nouns.

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

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

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

Other synonyms of handgun include pistol, side arm.

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