Jim-What were the ranges of your shots? If impact speeds were at 2750 fps or higher, it would not be uncommon to not have an exit. Did you recover any of the bullets? The elasticity of a deer's hide is pretty amazing, and I've seen numerous bullets that I'd have sworn would exit be stopped cold in its tracks.
A few years ago I watched a super-slow-motion video of a deer shot with a 165 grain Hornady SP from a .308 WCF. The hunter had 2 video cams set up, including one about 50 yards away from his location. The deer was facing directly away from this 2nd camera and nearly broadside to the hunter. At the shot, you could see the hide extend what seemed to be 8-12 inches away from the body as it "caught" the expanded projectile. If I can find the video, I'll post if. I've seen several similar to this, but this particular one caught my attention.
As to blood trails, even if a bullet exits won't guarantee one. As long as I get quick, clean kills, I am happy. And it sounds as if your excellent shot placement resulted in just that type of performance for you, too.
