Doc, just a heads up, I found some interesting info on the gen 3, 21SF’s with the ambi mag release. I learned that Glock had a lot of trouble with them and they were all 21SF’s. It seems that every once in a while, most of the internal release parts would just fall out the bottom of the magwell when the button was pushed. Glock decided to quietly exchange them for current models. I actually bought a 21SF with ambi mag release for $350 because I already knew Glock would trade it for a new one. Since I had a 21 already I exchanged it for a new 30SF. One thing I learned is when you call Glock tell them it’s a carry gun and you need all the serial numbers on the gun to match, otherwise they may want to give you a new frame and reuse your original slide.

Or, you could just keep it and try it for a while and hope nothing happens. I never even tried firing mine before I traded it back to Glock. Could be a rare issue or could be common. I have heard that once some departments got wind that the problem was occurring, they would not allow any of their officers carry one on duty. The gen 4 ambi mag release is a completely different design. Yes, gen 3, 21SF's are great guns, I love my non ambi 21.