dasMafia,
Hey you needn't do that, simply because the 416 Rigby is loaded down by almost everyone to about 2350 to 2400 FPS and has very little pressure,,that cleared up keep in mind that its perfectly feasible to load the Rigby up to 2700 FPS and I know some guys that claim almost 2900 FPS at max pressure...It is simply a 416 Wby without a belt, but the Wby does operate at Max pressure, but it has never been a problem that I know off....

All I am sayint is this low pressure legitamate claim for the Rigby really has no practical importance...Most all modern guns operate at 55,000 to 60,000 PSI and without pressure problems..The African heat is really over rated IMO, Ariz, Texas and California will give them a run for the money on any given day...and these guns work there also.

My therory is use a grain less powder than your worked up near max load and you will never have pressure problems anywhere and won't lose more than 20 FPS normally....Once any rifles peaks out then additional powder shows very little increase in velocity, but does in pressure...