I am wondering why the published load pressures for different powders vary by so much on the max load recommendations. Looking at this years Hodgdon loading data for a 168gr .308 bullet the max load for IMR 4320 is 46gr @ 59,300psi. The max load data for Varget is 46gr @ 50,600psi. Why do they not work up the Varget load to the higher pressure limits that they did the IMR powder? What causes them to stop 9,000psi short of where they stop with another powder? I see that the industry standard max pressure for the .308 is 52,000psi, why would they go beyond for some loads and not others? Just looking for a little insight on how the testing is done and why those choices are made.