One barrel at a time, kinda like an Over and Under shotgun . . Dunno if there's a select for barrel choice. And it's "Magna-Ported" to cut recoil, but I can't imagine, with the short barrels, that it would do much more than make a lot of smoke and noise in the daytime and provide a blinding flash at night . . Probably a hell of a good way to get an instant case of "Magnum Flinch" . .
The little Ruger LC9 9mm is just about as neat a gut gun as you can find. 6 shots, very little muzzle blast, not a lot of recoil and with the little laser sight that clips on the front of the trigger guard, deadly as hell up to about 10 yards . . And loaded with "Manstoppers", although a really short barrel won't give you max muzzle velocity, If you hit someone just about anywhere, you'll do more than just piss him off . . He's gonna be hurt . .