I've probably put between 750 and 1000 rounds through it so far. I've been using two Sig (one 1st gen & 1 2nd gen) and two Colt Mustang (1st gen design) magazines that I believe are made by Metalform. I ground off the front tab of them so they don't protrude past the frame.
Yesterday's session was the first one in which I used Sig's new 3rd Generation X-Mags, the primary reason for the range report.
Following my standard grip positioning with a right hand strong side 2-handed hold, my right thumb sits on the rear half of the slide stop. I can place my right thumb on top of my left thumb, indexing the tip of my thumb on my left thumb's basal joint or up in the air, but this doesn't feel especially natural.
I don't like relying on different hand positions with different handguns, as in a fight situation I'll just subconsciously put it right where it belongs....on the slide stop. With a strong side only grip, my thumb naturally rests between the magazine release and slide stop, and the slide locks back 100% with all my magazines.
Because it's doubtful I'd use it with a 2 handed grip in a fight, this is not a problem. Naturally, I shoot it 75% of the time one handed for the practice.
