Smith and Wesson Model 29

I know what you're thinking: "Did he fire six shots or only five?" Well, to tell you the truth, in all this excitement, I've kinda lost track myself. But being this is a .44 Magnum, the most powerful handgun in the world, and would blow your head clean off, you've got to ask yourself one question: 'Do I feel lucky?' Well, do ya, punk? - Harold Francis "Dirty Harry" Callahan

Cartridge: .44 Magnum
Action: Double action
Effective range: 50 m
Feed system: 6-round cylinder
Weight: varies
Manufacturer: Smith & Wesson

Well... It is not any more "most powerful handgun in the world" (actually, it was during movie's production), but it still kicks ass.