.600 Overkill

The .600 Overkill cartridge is a hunting cartridge designed to fit the CZ-550 action, by American Hunting Rifles.

Design
The .600 Overkill was designed by Robert Garnick of Las Vegas, Nevada, USA. The case is based on the .600 Nitro Express, with a belt [.683 in (17.35 mm)] added for headspacing and the rim to fit that of the .505 Gibbs [.640 in (16.26 mm)] size bolt face.

This cartridge was intended to be the largest bullet that was able to fit in the CZ-550, and was designed specifically for the purpose of elephant hunting. The CZ-550 is able to fit 2 cartridges, with slight alterations. The .600 Overkill fires a 900 gr bullet at more than 2400 ft/s,