The .276 Pedersen (7×51mm) was an experimental 7 mm cartridge developed in 1923 for the U.S. Army, intended to replace the .30-06 Springfield in semi-automatic rifles and machine guns. It was used in the Pedersen rifle and early versions of the M1 Garand, offering a shorter, lighter, and lower-pressure alternative to the .30-06. However, in 1932, General Douglas MacArthur rejected the cartridge after confirming that the M1 Garand could function effectively with the standard .30-06 round.