From Wikipedia, the free encyclopedia:
".303 British, or 7.7mmx56R, is a .311 inch calibre rifle and machine gun cartridge first developed in Britain in the 1880s as a blackpowder round, later adapted to use cordite and then smokeless powder propellant. It was the standard British and Commonwealth military cartridge from 1889 until the 1950s when it was replaced by the 7.62x51mm NATO.
The measurement .303 inches (7.7 mm) measures the nominal size of the bore measured between the lands (Europeans measured bore diameter land to land, Americans measure groove to groove.) which follows the older blackpowder practice. The overall size of the bore which is .311 inches (7,900 mm) nominal though bores for many .303 surplus military rifles often can be found ranging from around .309-inch (7.8 m) up to .318-inch (8.1 m).
This cartridge saw much sporting use with surplus military rifles, especially in Australia, Canada, and to a lesser extent, in the United States. In Canada, it was found to be adequate for any game except the great bears. In Australia, it was common for old military rifles to be re-barreled in .303/25 and .303/22.
Commercial ammunition for weapons chambered in .303 British is readily available, as the cartridge is still manufactured by major producers such as Remington, Federal, Winchester, Sellier & Bellot and Wolf. Reloading equipment and ammunition components are also manufactured by companies such as Hornady. Where extreme accuracy is required, the Sierra Matchking 174-grain (11.3 g) HPBT bullet is a popular choice. Commercially-produced ammunition is widely available in various FMJ, soft point, hollow point, flat-based and boat tail designs - both spitzer and round-nosed. The classic 174-grain (11.3 g) FMJ bullets are widely available, though purchasers may wish to check whether or not these feature the tail-heavy Mk 7 design. In any case other bullet weights are available e.g. 150, 160, 170, 180 and 200-grain (13 g), both for hunting and target purposes."
.303 British. (2009, March 18). In Wikipedia, The Free Encyclopedia. Retrieved 15:55, March 22, 2009, from http://en.wikipedia.org/w/index.php?title=.303_British&oldid=278192548