was on the site of Hambrusch/Ferlach and they have a new cartridge that look like a 50 bmg wildcat
http://www.ferlachguns.com/

The new Big Game Cartridge

Energie: E 11.450 Joule
Velocity: v 700 m/s
Bulletweight:
47 Gramm (722 grains)
Bulletdiameter:
14,02mm (.552inch)

Caliber: .600/538 MM
(Mega Magnum)

anyone knowing more about it?