Along with something like five iterations of 4831 the pressure specs for the 7RM and 243 were reduced at some point when they were both loaded with 7828 Data powder the bulk form of what we have now. Both had pressure excursions and wide variations due to the different chamber specs and throat erosion.

Different methods of pressure testing and different barrels will produce wide variations in pressure. As the old copper crusher receivers were phased out the electronic psi barrels gave different and probably more accurate results.

On a long throated almost free bored 7RM I just split the difference between the 7RM and 7 Weatherby. I use only powders slower than R22 so it is difficult to put too much powder in the case. Max loads that fill the case with light compression only work best for me and an overcharge will spill out of the case.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli