First off a great piece of engineering from the the PistolGear.com guys!! This thing mounts solid and has a huge opening. If you miss this thing on a reload you need serious help. With the Arredondo base pads it really works well.
The front of the mag well locks into the ridge in the front of the frame, then it has a threaded rod that goes through the interchangeable back-strap and locks the back of the magwell tightly in place. Mine doesn't so much as wiggle in the slightest bit. This really is a quality piece. There are a couple of ways you can go about installing the magwell
1. Slap it on your pistol and let it ride. (works fine just like that)
2. To make is silky smooth on the reload bust out the dremel, a sharpie, and some very fine grit sand paper. (That's what I did)
A. Place the magwell in the pistol and mark the exposed area of the frame with the sharpie.
B. Take the dremel and remove (slowly) the marked areas.
C. Repeat A.
D. Smooth out areas with fine grit sand paper
E. Install magwell
Total time??? About 20 min
Thanks to Scott at Pistol Gear for another quality product. (mine had already gone through two matches and lots of practice reloads before the pictures had been taken)