Your not using a 45, are you?
I will be usin one this fall. FWIW, I have shot more than a few deer in my lifetime with everything from 12ga rifled slugs to .50 patched balls. Of all the deer I've taken with patched balls in .50, .54 & .58cal., complete pass throughs have been the norm and I can honestly say that I have had more deer drop in their tracks, after being hit with a heart/lung shot from a patched ball, than I have had with 1oz rifled slugs or any lead conicals.
Those deer that have run after a heart/lung hit with a patched ball haven't run any further, on average, than those that have run after a like hit with rifled slugs or conicals. Of course I haven't kept any exact statistics, but I would even say of all the deer that have run after a heart/lung shot with all projectiles, those hit with the patched ball have run less on the average.
I do alright tracking myself and I have never had any problems tracking any deer shot in the heart/lung area with a patched ball. I have also never had to track any deer, shot with any projectile, in the heart/lung area, for more than 120-140 yds. YMMV.
These have been on shots from 10-85 yds, with most shots under 60yds and I do use pretty stout powder charges when hunting with patched balls. I have no doubts that a 60 yd or less heart/lung hit with a .45cal patched ball ahead of 85-90 grns of Ffg, will bring down any deer within the same 120-140 yds. IMO, if I can't track a mortally wounded deer for 140yds, even if it leaves no blood trail, I shouldn't be shooting it with anything.
There is a very interesting article in the latest Muzzleloader magazine, written by Mike Nesbitt, about hunting with round balls. It discusses a lot of the same arguments against roundballs that have appeared in this thread. Mike does an excellent job of either debunking most of those arguments or putting them into the proper perspective.