Lee I will check the locking mechanism, that is something that I haven't paid much attention to. Loads and bullets are the same. End of the barrel is fine, no dents or scratches. The rings are even spaced on all sides, so there shouldn't be any torque problems there. No quick release Dave, solid mounts. Not really sure what is going on here, but I'm gonna shoot again in the morning to see if its still on. Something that I thought about is when the gun is put back together after cleaning the pin is what aligns it up. If something is wrong with alignment will that cause this problem? The scope being mounted on the barrel was making me think that it wouldnt, right or wrong? I should have mentioned that windage was perfect the problem was elevation alone. Also this is something new, I have had this gun for 3 years with no problems. Just started this season, it cost me a nice buck would hate to have that repeated. Might just have to use the ole trusty white or rem 700.