IMO its a 50/50 call. usually, when serious bone is hit the .500 NE does not exit. When no such bones are encountered, they freqently do exit. (Mostly seen Wolfgang Romey ammo, thus Woodleigh bullets.) As an aside, I shot a wounded tuskless cow last year on the last rib, going away, and the bullet exited on the opposite cheek. {{Edited- see post below}} (500 gr GSC @ 2450 ft/sec). See photo below