shooting iron vs handgun

shooting iron and handgun both are nouns.

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

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

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

Other synonyms of shooting iron include pistol, side arm.

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