Well, I just went through all of that commercial brass. As it turned out, there was mostly RP brass, which I sorted, and was able to find some once fired RP brass that I had shot from the factory. I weighed the difference between the RP brass and the Winchester brass I have (fired w/ primer still in it), and it all came out to about 96 grains each, +/- 1 grain. So it appears I can safely load the RP brass with the same load as my Winchester brass. Anyone have anything to prove differently?

Thanks.