I shoot 777 because it is cheaper and available. I swab between shots, which lets the barrel cool down, and means every shot goes where the cold barrel shot goes. If you do it right, you only need to shoot once when hunting.
Powder is cheaper and usually more accurate because you can adjust the load to your rifle. It also give higher velocity than pellets for the same grain load. Buy some small tubes to carry preloads while hunting. It is just as fast as pellets.
My friends have good luck on both deer and elk with thier Accura's using Barnes 290 gr. Expanders with about 120 gr. of 777. I carry the breechplug wrench in the field in case something goes wrong and I need to remove the breech plug. Use some automotive Anti-seize compound from an auto store, and your breechplug won't ever stick. Winchester 209's fit my .45 Accra breechplug the best without blowback.
I bought a couple of Lee sizers for my .45 and have used them to size .45-70 bullets down to .451. The manufacturers know what fools we are and price muzzleloader stuff accordingly. You can buy 350 gr. .458 Socom from Berry Bullets for about .$0.36 each from MIdway. Add a Harvester Crush Rib Sabot for $0.20, and you're way cheaper than most muzzleloader bullets you'll find. A 350 gr. bullet will stop a deer in its tracks, and will work on elk too. A bullet that big doesn't need a lot of powder behind it, so the recoil isn't bad.
Lots of folks believe that a 209 primer is too hot for 777 powder. It does make a crud ring, and some believe it actually moves the bullet before the powder ignites. I don't believe it moves a 350 gr. bullet. They make special reduced power primers for 777 and sell them at exorbiant prices. I found some old Federal 410 reduced power primers at a gun show that work fine, but come out black (blowback). Search this forum for shims and O-rings for how to stop blowback. Good hunting and Happy New Year.