My light 1000 yard BR gun is a 7mm Rem with a Hart 28.5 barrel. I shoot 176gr GTB bullets with 65.5gr VV-170. I use RWS brass and Rws Mag primers. Twist 1/9 and I need 2950fps to make this combo work. I put a new Schneider barrel on it and rechambered in a 7mm Rem mag IMP. With 68.8gr of Retumbo...