gunslinger vs shooter

gunslinger and shooter both are nouns.

Word	Noun	Adjective	Verb	Adverb
gunslinger	Yes	No	No	No
shooter	Yes	No	No	No

As nouns, gunslinger and shooter are synonyms defined as:

Other synonyms of gunslinger include gun, gun for hire, gunman, hired gun, hit man, hitman, torpedo, triggerman.

gunslinger (noun)	shooter (noun)
a professional killer who uses a gun	a large marble used for shooting in the game of marbles
	a person who shoots (usually with respect to their ability to shoot)
	a professional killer who uses a gun
	(sports) a player who drives or kicks a ball at the goal (or a basketball player who shoots at the basket)
	a gambler who throws dice in the game of craps