444 loading data for 1894 Win. Big bore

An opportunity has come my way to purchase a Winchester 1894 AE .444 Big Bore. I seem to recall reading at one time or another that the Big Bore 1894AE could handle pressures higher than the Marlin by about 15000 PSI.
If this is true then it strikes me that separate loading data must exist for this rifle; much the same as 45/70 data does for the different rifles it comes chambered in. If it does then it must be well hidden because extensive searching on all the various available reloading sites turns up squat, nada, zero. nothing.
Does this mean that the '94 .444 doesn't handle the pressure or am I not looking in the right places?
Any one with proven and verifiable data (with the usual disclaimers of course) willing to give me a hand here?
Thanks all.