I'm loading for a 30-378 Accumark. I'm using Retumbo, Berger 185 VLD. Berger manual max load is 107.5 gr but only 3184 f/s. I want to reach speed top speeds, around 3400 f/s. I do not have a chronograph but do know how to look for overpressure. I'm hoping somebody would share previously worked loads for this specific rifle, powder, bullet combo.