It was also with Norma that Weatherby finally found a source for loaded ammunition.

The cartridge is able to fire a 300 gr (19 g) bullet at 2,800 ft/s (850 m/s) generating a muzzle energy of 5,224 ft⋅lbf (7,083 J)[4][5] with the trajectory of the 30-06 Springfield.

This performance level makes it an appropriate all-round African safari cartridge that is usable against plains game species as well.

The .375 Weatherby is considered overly powerful for North American game.

The parent case is based on the .300 H&H Magnum blown out and necked up to accept a .375 in (9.5 mm).

The velocity gain over the .375 H&H Magnum works out to be about 240 ft/s (73 m/s) and an increase in maximum point blank range of about 25 yd (23 m) with bullets of equal weight.