10mmman, not directly related to your question, and probably something you already know, but I'll tell you of my stupidity.
Just a couple of months ago, I bought a new MKII that was pre-drilled and shipped with the factory base and 1" rings. In addition, I purchased a red dot scope to complete the package.
As I had just joined a club, I was all pumped up to get things zeroed in. I just knew if I had the latest hot rod, I could produce the same excellent scores several of the other members had.
I went to a local indoor range and ran over 200 rounds through it. I had the both the iron sights and the scope dialed in perfectly. I was ready!
Two days later I went to the club meet. On the first target, the first 5 shots were great! Then, things went downhill. I couldn't hit the ten ring if my life depended on it.
Scratching my head and inspecting everything after that round was over, there it was: The scope was actually broken/cracked at one of the rings. And why was it broken? Both thumbscrews that tighten the rings to the base had loosened. The thing had shaken itself to destruction. (Let's face it, even these little 22's exhibit quite a bit of shock to its parts.)
I'm usually fairly careful about checking my equipment and making sure I'm using a safe firearm. However this time, I think my want of those great scores got the best of me.
Moral of the story: Don't be a dummy like me and fire hundreds of rounds without checking the scope mounting screws. Check them regularly!
Regards