Are your load manuals from different bullet manufacturers?If so, remember each uses different componants.Also,example, a Sierra bullet is going to differ in certain ways to a Hornady or speer,even though it is the same weight and style.Classic example is a Sierra 230gn. FMJ max gn.bullseye is 5.2. Speer 230gn. FMJ max gn. bullseye is 5.7.Bullet design has direct bearing on pressure.