[ithacaartist]

Geoff, I've encountered both under-size magazine wells and a variety of overall related dimensions on their mags. I did a check fit of all my KGP69 mags in all my KGP69 pistols. I came up with effectively Large, Medium, and Small in both categories, and paired the mags with the pistols they fit, marking SN of each gun on the mag(s) that fit it.

Don't modify that mag any further because it simply "belongs" in a KGP69 that happens to have one of the Medium of Large mag wells. The luck of the draw will eventually provide you with a mag that fits nicely, so buy some more and sell this one until you have some that work--which is what you want.

In the case of a mag that "allllll-most" fits, a 1/2" square file works great to carefully shave the rear of the mag well a bit. Keep watch of the subsequent raw metal so it doesn't corrode!