I use FFFg in it and I love it. Its finer than FFg and seems to burn better. Do a test with Pyrodex, Triple seven and Pioneer. Shoot each and swab the barrel between shots and look at the patches then you'll see why I love it. Jim Shockey even endorses it now.
Have you noticed the moisture absorbing properties of American Pioneer Powder. People seem to hold that against the powder claiming it sucks moisture out of the air like a sponge in a lake. I've shot a lot of it, but never noticed the moisture problems, but then I never hunted with it.
I also agree, if you buy it get the 3f grade. The 2f is so course that it will not even pour out of a powder measure. It is like fish tank gravel. Right now I am shooting 3f Pinnacle. I like the powder a lot and have had some real good luck shooting it. If the load I am pushing will hold true, I might give it a try during our modern season. So far the stuff does not like heavy projectiles. Have you noticed that with APP?