My advice is to shoot it some, find out what the most powder you can shoot and still get groups out of, within safety of course. My TC Blackdiamond XR shoots 120 grains of pyrodex and a 325 grain bullet great, but any more powder and it starts throwing shots. Haven't shot an elk with it, but I have shot deer and it dropped 'em. My friend has the same gun and his will shoot better with only 100 grains of pyrodex so you never know. Generally rule, more powder is better for killing power as long as it groups.