Hi have changed gun (308)and the new one has shorter barrels, 20 inch. My previous loads did not group well so changed the OAL a bit and they improved but are still 2 inch groups at 100 yds. Have also increased charge from 43 to 44 gr with no significant improvement. My question is that with shorter barrels am I loosing accuracy because the bullet will be travelling slower? Should I increase the load further to increase muzzle speed? Will this more than likely increase accuracy?