Thanks; I'll keep that in mind. I have a 5/64" allen wrench and I used that to tighten up the rear sight. Like I said earlier, some techie at the factory probably just forgot to tighten both of the screws all the way. It was rather odd because I am fairly decent using a peep sight, and then I noticed that the rear sight was loose. That was after I had shot almost all my ammo up.I would try some light-duty Loc-Tite on the rear sight screw once everything is adjusted properly. In my experience, they will shoot loose rather quickly. Stick with Ruger mags for all serious use; the others can be good range mags, but that would be all I'd use them for. The Mini is a rugged, reliable little carbine, fun to shoot, easy to maintain and cheap to feed.
Next time, I take the two factory mags, my spotting scope and a few of those orange sticky dots out and see if my little fix worked.