text: The M1906 maximum range was originally overstated. When the M1906 cartridge was developed, the range tests had been done to only ; distances beyond that were estimated, but the estimate for extreme range was incorrect by almost 40 percent. The range discrepancy became evident during World War I. Before the widespread employment of light mortars and artillery, long-range machine gun "barrage" or indirect fires were considered important in U.S. infantry tactics. When the U.S. entered World War I, it did not have many machine guns, so it acquired British and French machine guns. When those weapons were later replaced with U.S. machine guns firing the M1906 round, the effective range of the barrage was 50 percent less. Firing tests performed around 1918 at Borden Brook Reservoir (Massachusetts), Miami, and Daytona Beach showed the actual maximum range of the M1906 cartridge to be . Germany, which was using the S Patrone (S ball cartridge) loaded with a similar  flat-based bullet in its rifles, had apparently confronted and solved the same problem by developing an aerodynamically more refined bullet for long-range machine gun use. The s.S. Patrone was introduced in 1914 and used a  s.S. – schweres Spitzgeschoß (heavy spitzer) boat-tail bullet which had a maximum range of approximately .
  .30 M1 ball cartridge
  For these reasons, in 1926, the ordnance corps, after extensive testing of 7.5×55mm Swiss GP11 projectiles provided by the Swiss, developed the .30 M1 ball cartridge loaded with a new improved military rifle (IMR) 1185 propellant and  bullet with a 9° boat-tail and an ogive of 7 calibers nose cone that had a higher ballistic coefficient of roughly 0.494 (G1 BC), that achieved a muzzle velocity of  and muzzle energy of . This bullet further reduced air resistance in flight, resulting in less rapid downrange deceleration, less lateral drift caused by crosswinds, and significantly greater supersonic and maximum effective range from machine guns and rifles alike. Additionally, a gilding metal jacket was developed that all but eliminated the metal fouling that plagued the earlier M1906 cartridge.
  The loaded round weighed  and its maximum range was approximately . The maximum average pressure (MAP) was . The average target radius was specified to be not greater than  at  and not greater than  at  when fired from a Mann accuracy weapon.
  Cartridge, caliber .30, ball, M2