How do you unlock more guns in Resident Evil 4

Beat the game with Leon to unlock the infinite launcher, it has to be bought. beat separate ways to unlock Chicago typewriter(Tommy gun,infinite bullets). In mercenaries get a five star ranking on each level with each player to unlock the handcannon. Beat the game with leon on pro difficulty to unlock the laser cannon. Or if its your first time playing it, as you progress through the game more guns will be unlocked.