Without a doubt that honor goes to the. 50-cal. Magnum handgun from Smith and Wesson. This is known to produce over 2,500 foot pounds of muzzle energy, way more than a. 44 magnum or. 454 Casull. Even the. 480 Ruger and. 475 Linebaugh have nothing on this monster. This is the by far the largest double-action revolver cartridge ever created.