The 505 Gibbs roun was invented in Bristol, England in 1911 by George Gibbs. The round was originally known as the .505 magnum, and has a case capacity of 161 grains (10.4 g). Loads can be made up to over 9,000 ft·lbf (12,000 J), 2,600 ft/s (790 m/s) with a 600-grain (39 g) bullet.