.400 H.& H. Belt.Mag

The .400 H&H Belted Magnum cartridge, also known as the .400 H&H Magnum, is a rifle cartridge that was developed by Holland & Holland in the 2000s and is based on the .375 H&H Magnum case.

The .400 H&H Belted Magnum cartridge features a belted brass case with a bullet diameter of .410 inches (10.41 mm) and a case length of 2.85 inches (72.39 mm). It typically uses a 400-grain (26 g) bullet propelled by a powder charge, which gives it a muzzle velocity of around 2,700 feet per second (820 meters per second) and a muzzle energy of around 5,500 foot-pounds (7,460 joules).

The .400 H&H Belted Magnum cartridge was designed to provide hunters with a cartridge that had similar ballistics to the .416 Rigby cartridge, but in a smaller and lighter package. It is primarily used for big game hunting, particularly in Africa and other locations where large, dangerous game is present.

However, it should be noted that the .400 H&H Belted Magnum cartridge is a relatively new cartridge and is not widely available. Firearms chambered for this cartridge may also be difficult to find, as it is not a standard or popular cartridge.