A lotcompare the holes in the carcass not the hide. Your right usually the bone smashes in but I have seen cases where it doesn't. Perfect example was last elk season 300RUM200 AB, hit smack on the rib bone at 1/4 awayangle and finished through just behind the opposite leg. When we arrived to the scene to help drag out the bull the usual conversation transpired "details of the opportunity". Showing us where he shot him and the blood trail I found a 2" chuck of rib bone that was flushed out in his scamper, it was on the entrance side of the trail. This elk had a chuck of hide missing on the entrance where the rib bone fell out, the exit side of things was actually pretty similar 2-2 1/2" hole in the hide from the bullet exiting the animal. Everything in between was a mess as per usual. I suspect that the angle/hit, design and velocity caused the rib bone to actually go out vs in.

Only point is you don't know how a bullet will behave or act when it strikes it's target a lot of factors to contend with. So really just a guess, put it in the lungs and get notching your tag...