These are British Army issue clearing plugs (split case extractors) for .30" weapons firing the .30-06 cartridge (7.62x63). Issued by the British primarily for use with the .30" Browning machine gun, they were also used with the M17 Enfield rifles bought from America in the early years of the second world war for use by the Home Guard. They can be used with any .30-06 weapon including the BAR or the '03 Springfield. Good to excellent used condition. Stock No 7/17.