I mentioned this in another thread, but I shoot 80 grains of Triple Seven with a 295 gr. Powerbelt. That combination is plenty of powder to do a lot of damage to a deer, plus I've read that Powerbelts don't like a lot of powder. It's the combination that seems to have the best accuracy for me. If I'm just plinking at the range, I use patched roundballs with 40 gr. powder to practice trigger control, sight picture and breathing. At 50 yards that combination hits maybe 3" max below a full load Powerbelt. And it's a lot cheaper and a lot easier on the shoulder.

But in the end, it's what combination of rifle, powder and projectile works best for you. There is no single correct answer.