[Tijeras_Slim]

.308 = 7.62x51

[mountainlion]

308 = 7.62x51

Thanks. I forgot. I think 50 BMG is 12.7 x 98MM

[Myrddin]

.308 = 7.62x51

.308 Winchester is a SAAMI spec. 7.62x51 NATO is a NATO spec. The NATO spec is lower pressure. There are also significant geometric differences in the brass.