I am shooting a 338 lapua using AI magazines. I find my oal is limited by my magazines 3.5" maximum. Once I drop a 300 grain bullet and 94gr of H1000 I am concerned that I will not be able to get an accurate load. I still need to break in the barrel, chrono the loads and of course measure the actual seating depth against the rifling. Really I guess my question is; what is the minimum oal with all the above?