unrifled vs smoothbore

unrifled is not a noun while smoothbore is a noun.

Word	Noun	Adjective	Verb	Adverb
unrifled	No	Yes	No	No
smoothbore	Yes	Yes	No	No

As adjectives, unrifled and smoothbore are synonyms defined as:

unrifled and smoothbore: of a firearm; not having rifling or internal spiral grooves inside the barrel

unrifled (noun)	smoothbore (noun)
	a firearm that has no rifling

unrifled (adjective)	smoothbore (adjective)
of a firearm; not having rifling or internal spiral grooves inside the barrel	of a firearm; not having rifling or internal spiral grooves inside the barrel