Went out to check zero on my rifle this afternoon befor I went to my bear stand. I put a shell in the action, and threw the bolt ahead, but it wouldn't chamber the round????? not sure why, the bolt is about 1/8th of an inch from being all the way forward. Not sure what the issue is. I used the rifle alot last year with no issues. It is factory ammo, and I tried a couple different brands, both with same result. So the question, WHAT THE HECK IS GOING ON??????? Head spacing screwed? How do I fix it?