Because I'm currently down in FL and don't have access to my load manuals I'll try to explain my method. What I try to find is a load somewhere in the middle of the charge range that will fill the case to the base of the neck. My favorite load for the .243 and .270 win. example were 40.5 gr and 54gr of IMR4350. Both of these loads were extremely accurate in my rifles and the load for the 270 was accurate in several other rifles that they were tried in. I try to avoid using compressed loads.