Surprised you even found the bullet with a 50 yard shot. I have been shooting 460 grain No-Excuse Bullets and they have never been able to recover one. Even 200 yard shots at deer.
Could of you had a short load?
Did the shot feel strong as usual?
Never saw in a rifle round do this, but have seen it twice with Barnes bullets in a muzzleloader. Once a 300 MZ, and the other a 290 TEZ. They did not stabilize in sabot, in a slow twist Hawken and reversed before/during entry. Perfectly round entry hole, no deformation, and half of normal penetration
Full load and everything felt normal. It was a frontal shot, quartering to. just right of the brisket/neck and in between shoulder. Bullet was lodged in the opposite shoulder. It wrecked a lot of internals and killed him quickly. Ran about 80 yards. Just never thought the bullet would look like that. And yes, I though about shooting another animal with it just to say I killed two deer with the same bullet. Lol.
Here’s a Thor that got shot thru a sheet of plywood and into the bank behind it. You can see it knocked the polymer tip off.
My only field experience is one bull elk thru the ribcage. The entrance hole was .502, and the exit was about .503. Fortunately he just stood there and died. I’m going with hollow points next time.
I shoot Hornady 300 gr in my ML. Don't think I've ever recovered one. Usually a pass thru. I think most of the exit holes are bigger than the entrance but can't say I've paid much attention when everything has died within sight. I'll pay more attention next time!
Not that I think about it, I did recover one once. Petals were back so it expanded. But that's only one out of many.
Sorry, but I still think it was a short load, semi bad powder, not loaded right, etc. At 50 yards it should of blown right through it. Even at 150 to 200 yard quartering and broadside shots at deer have alway exited for me. Even elk at 125 to 150 yards. Given I mainly shoot 460 gr. No-Excuse Bullets, but I have shot the Barnes all copper years ago too.