Hi there looking for the best load useing Varget powder.I am useing boat tail sierra 85 gr hp 1530.My rifle is a 6 mm br and the twist is 1*8.What is the best way to find my right load .Is it better to have the bullet sitting on the rifting at the start our would have it back from the rifling 10 our 20 our 30 back where would you start please