RE: Black Powder loads.
txhunter I learned the same lesson you did with powerbelts. The first bunch I had I tried all the magnum loads and after seeing the group decided this was not for me. A friend told me to cut the charge to 80 grains and work my way up. At 90 grains of loose Pyrodex powder, the 348 grain aero tips shot fantastic. I know this would make an excellent elk load. It should give you great penetration and release a lot of it's energy in body for the shock effect you need to bring them down.
Of all the rifles I have, not one of them shoots its best groups with a maximum load it can handle. The only one that comes close is the Black Diamond XR and even at 120 grains of loose powder it will hold tight with certain projectiles.....