I shot a doe with my Granddad's 50 cal. Hawken PRB pushed by 80 gr. of T7.

She came down the hollow and crossed at the head of the ravine right in front of me, I shot her broadside at about 30 yards. When I got all the way down the hill to her (too bad deer never roll up hill) I could not find an exit wound. I thought "hmmm... thats odd" but whatever I was happy. During the butchering process I found the round ball smashed flat on the backside of her onside (the side I shot her from) shoulder blade.

I could never put together what exactly happened.

Any Ideas?