The 6mm XC was initially developed as a
Wildcat cartridge specifically for
NRA High Power match shooting by 11-time US National Champion
David Tubb. The round originated from chambering a barrel using a
.243 Winchester reamer held short, with the case reformed from
.22-250. It is touted as being one of the most accurate long-range
6 mm rounds in the world that is designed for repeating rifles. The 6XC is now a
CIP standardized case. The origin is listed as Sweden since Norma standardised the case. Factory brass is available from Norma and Peterson. ==Performance==