When Billy Ray Valentine (Eddie Murphy) is surounded and arrested by the police, the officers are seen armed with Smith & Wesson Model 10 revolvers.
Colt Commander
Louis Winthorpe III (Dan Aykroyd) sees a Colt Commander with pearl grips at a pawn shop. He asks how much. We see him with it sometime later. He appears to have successfully purchased the gun, though likely without a pistol license.
Hunting Shotguns
When Winthorpe and Billy Ray join together to take down Randolph Duke (Ralph Bellamy) and Mortimer Duke (Don Ameche) for wrecking their lives with a simple bet, Winthorpe takes out several 12 Gauge Double Barreled Shotguns, planning to shoot the Duke's knee caps.
Astra Constable
Clarence Beeks (Paul Gleason) draws an Astra Constable on Winthorpe when he realizes he is in disguise and holds it on Ophelia (Jamie Lee Curtis) before he is knocked unconcious by a caged gorilla and has it taken away by Coleman (Denholm Elliott).