I came up on these two deer two years ago on a crop damage hunt. They were about 10 yards apart.
I had my 7 1/2" FA .454. Dropped the one on the left in it's tracks with a 260 gr. Speer HP at 99 yards. The one on the right froze up, confused. The second bullet in the cylinder was a 265 gr. Swift HP. She dropped in her tracks at 102 yards.
The damage from the Speer was 2 1/2" internally, and 3 1/2" internally with the Swift.
These are the only two bullets I use on deer. I actually recovered 5 300 gr. XTPs from deer. My thinking is that if can't penetrate our smallish WV whitetails , then they're not for me. The Speer and Swift were total penetration.