I find a hard time getting acceptable results from full 150gr loads. But have found that you will blow out most loose powder, but with pellets, they burn pretty efficiently.

I don't blame you for wanting more go go juice. Give 3-50gr 777 a try. I got 3" groups with barnes expanders or knight redhots with 2000fps give or take 50fps. its tough getting the sabots down, but has less blowby. Then find you a real accurate, backup. Mine is 95gr of pyrodex with 240gr xtps. Consistent 2" groups at 100 yards. Nothing is wrong with experimenting. Don't let anyone tell you different. Recoil isn't near as bad as some of my magnum rifles, so thats not a real problem either with 3-50gr pellets. Muzzleloader barrels are hard to wear out. You would wear out 2 270wins before one muzzleloader barrel. A quality one anyway. So shoot away. And let us know how it worked.