Well for starters I want to say thank you for all the opinions given thus far. Never thought this thread would generate such hot debate.
Reading all the comments just wanted to clarify some points.
1. I have killed 9 deer with this rifle, 5 with 180 grain soft point (factory Federal Power Shok, no exits) 2 with 168 grain Sierra Match King BTHP, 2 with 208 grain Hornandy A-Max.
2. 300 WSM is alot of gun for whitetail, sure is. This rifle was built as a beanfield rifle, it has Teludyne Tech Straightjacket barrel System and muzzle brake. Given the extra distance of southern soybean fields I tailored some long range loads to it, that would give the extra legs in velocity and ft/lbs at extended range.
3. The deer in question, the jacket, whats left of it was found on the opposite side of the impact just almost through the hide. What happened to core? Good question but when I was cleaning the deer at the processor there were alot of bone and lead fragments.
4. The chest cavity looked like a small bomb went off, a solid punch through the ribs, and massive destruction to the vertebrae at the top of the chest cavity. Next time I will take a picture.
5. I am aware that Hornandy says not to use this bullet for deer, clearly yes when the jacket and core separate the bullet failed. Its hard to believe that this bullet in this caliber, generating over 3,100 ft/lbs is "inferior" for killing whitetail.
My OP was directed not so much at the AMAX but at all the bullets I have tried thus far being unable to exit. Of the 9, 4 were shot center chest, the rest have all been mid shoulder hits. I find this peculiar. All deer have been DRT, hence the "2-Foot Rifle" nickname, not a complaint, just wanted to know how it could be I not was getting any through through shots.