|Ok first of all, gotta say the obvious, this is NOT a GLOCK factory mag!!! Now with that said, I got the mag in very quickly, and when I first ran it through the motions-loading, unloading, cycling, etc, everything worked great. Oh by the way I should add that I didnt use this in .40 S&W.
I have a Glock Mechtech carbine in .357 Sig. The mag worked flawlessly, but I did thouroughly inspect it before hand. I have a 9mm 33 rnd mag that I had to take off the plus 2 extenstion because of jamming issues. So far I havent had the same problem with this one. I plan on buying at least one more of these!! one thing the description doesnt tell you is that the mag is textured on the sides where it sticks out of the mag well, which was a bonus to me.|