FWIW, I have noticed with my kills that the .50 up to 100 yard + or - after hitting the deer seems to bang around in the body like a pin-ball. On the other hand my .54 at the same distance will enter and stay more in line with the shot. That being said with both I use a 2F charge of 70 grains and Hornady .490 and .530 RB's with buttered .015 ticking. Just my 2 cents worth. Note: To date not a single deer took another step once hit from any Muzzy shot I ever took. Somthing to be said for the knock-down power and velocity of Black-powder (flintlock) hunting.
This is one of those your mileage may vary things.
If you hit a major bone a 50-54 may deflect. But so will a lot of other projectiles. I have had "new and improved" 45-70 factory ammo deflect radically 2 for 2 with no major bones struck.
I have done straight line pass through with both on deer at various ranges. I have had straight through pass through to 140 yards or so with both.
I have very seldom had a deer pile up in its tracks. 99% will run no matter what they are shot with. Some go a short distance some will go long distances. Most drop to the shots involve a ball/bullet close to the spinal column. I have seen MD bucks shot high chest with a 7mm mag and lug hanging out the exit wound make 150 yards +
The last deer I dropped in its tracks that hit no major bones was a buck I shot with the 16 bore. This passed through the center of the shoulders without hitting a major bone.
But he, unknown to me had been whipped in a fight with another buck and likely was not 100%.
I shot a doe with the same rifle at about 40 yards end on massive damage destroying the heart. Deer turned 90 degrees and ran 55 yards. I really have not shot enough deer with this to make a scientific study. I have shot a deer with a 38-40 BP load and while it killed about as well as anything else the tiny wound channels convinced me not to do it again.
I have had a WT doe shot nearly identical to the buck above with a 54 straight through pass through at about 25-30 yards deer turned 90 degrees and piled up 200 steps across the hayfield. But note that her feet only touched the ground 10 times, I counted, in that time and she landed dead and slid to a stop on the snow. 100 gr of FFF, 530 rb close range and the deer ran off with no reaction to the shot.
I am only stating this so that folks that shoot deer and they run off will not think they have a problem. It all in how things work out. Some critters will fall over shot with a popgun others run off with large holes where vital organs used to be.
Much of it is mind set on the part of the deer (Elk, Moose etc) and its level of excitement before being shot.
Sir William Drummond Stewart (IIRC) stated that it was easier to drop an Elk on the spot with his 20 bore rifle than a Deer.
Dan