GREAT SHOT AND GREAT BUCK!!! If you practiced at 50 yds good on you for making the shot. It's a tough one no matter what. Who cares about ground shrinkage, I bet you were pumped regardless. Kudos to the pops for finding it. BTW, people take 50 yd shots at Muley's on a daily basis this time of year. It's no different, if you train for it and are comfortable with the shot in the moment of truth then take it. If there is any reservation whatsoever, you owe it to the deer (and yourself) to let off the bow.
VA