Description

50 factory new WINCHESTER item #WNU303 unprimed 303 British brass rifle cartridge cases.

Winchester item 3 WSC303BU

History: The .303 British rimmed rifle cartridge first developed in Britain as a black-powder round put into service in December 1888 for the Lee–Metford rifle.  Three years later smokeless powder was used.  The 303 British was the standard British and Commonwealth military cartridge until the 1950’s

RELOADING PREPARATION:
Brass case mouths MAY not be perfectly round from the manufacturing process, this can be corrected by running brass through the size die (always recommended) prior to loading. Residue from the annealing process may leave a stain on the case neck that can be removed by tumbling. Annealing involves rapid heating then cooling to impart the shell cases with the proper hardness to securely hold bullets in place and provides flexibility to expand and contract through multiple firings handloaders expect.