Best load in my .50cal MK-85 is the Hornady .452/300grn XTP/HP with 100grns Pyrodex-RS and/or pellets...dropped several deer in their tracks with it using a high shoulder shot.
One was the largest racked mature 8-pointer of my life at 165yds in a beanfield...still have that recovered bullet, expanded and mushroomed to the size of a quarter, looks exactly like one of Hornady catalog photos...the energy transfer at impact is simply devastating.