I have confirmed that my manual says the maximum recommended loose powder load is 100 grains of 2f granulation .Oddly, they recommend a 100-130grain load of pellets. So they recommend at least 100 grains of pelletized powder. I'm shooting loose and I won't exceed 100 grains 777 2f. I feel perfectly safe with that, and I don't see anything in the manual which would prohibit that load. I recently purchaseda pound of777 2f powder BTW so I might see how she fires in the Apex soon.

Added:

My sense is that rather than saying the limit of BP is this amount, the limit of Pyro RS this amount, and so on . . . BPI has elected to restrict the total loose amount to the most powerful of the approved loose powders. No matter what you use, no more than 100 grains is the maximum. I can see the wisdom of this approach as there can be no way to overload load the rifle, regardless of powder chosen, if 100 grains is the maximumone loads.