smoothbore vs unrifled

smoothbore is a noun but unrifled is not a noun.

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

As adjectives, smoothbore and unrifled are synonyms defined as:

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

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

smoothbore (adjective)	unrifled (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