Pfeifer Zeliska .600 Nitro Express revolver

The .600 Nitro Express Zeliska revolver is an Austrian single-action revolver produced by Pfeifer Waffen. Except for the Giant 1859 28mm Remington revolver, the Zeliska may be the largest handgun in the world, weighing in at 6.001 kg and having a length of 55 cm. The cylinder alone weighs 2.041 kg. The Zeliska is one of the most powerful handguns in the world, producing a muzzle energy of 4,592 foot pounds (by comparison, a 14" revolver chambered in the .500 Bushwhacker cartridge achieves approximately 10% greater power, firing a 310 grain bullet at 2,714 fps for 5,071 ft. lbs. of muzzle energy or a 400 grain bullet at 2,403 fps for 5,130 ft. lbs. of muzzle energy ). The weight of the handgun helps control the recoil, making controlled shooting possible. The capacity of a Zeliska is five .600 Nitro Express or .458 Win Mag rounds. The Zeliska fires a 900 grain (58.32 g) .600 Nitro Express slug at 1,516 ft/s (462 m/s, 1,663.2 km/h). The cost of a Zeliska revolver is $17,316. Each .600 Nitro Express round costs $40, making this gun very expensive to fire.

Loading is accomplished through a loading gate located on the right of the cylinder, similar to the Colt Single Action Army, upon which the Zeliska largely is based.

Added features to the gun include gold-plated hammer, cylinder pivot, action and the gold-filled inscription on the gun indicating the company's address.