I used to run a 6.5 x 57 AI in F Class, using 45-46 of 4350 in a 30" barrel it would launch 142 SMK @ 2950ish, barrel life around 2000 rounds, depending on accuracy requirements, case life was excellent using RWS 7 x 57 cases and forming to suit, BUT the same barrel rechambered in 6.5 x 47 using...