RickB,
I have purchased several Wilson Sentinal Magazines for my Detonics CombatMaster MKVI. They extend about 1/8" - 3/16" past the bottom of the grip. I installed a Ed Brown mag well with removable well and they fit and look great. I epoxy a 1/8" solid rubber O ring piece to the top of the pad at the front. The O ring just compresses as the mag locks into place preventing play and over insertion. Just cut the Home Depot O ring with a razor blade to the size needed. I feel the Wilson magazines are superior to the stock Detonics or the Metalform replacements from Brownell's. I have the 6 and the 8 round Sentinal mags. Without the mag well your mag will stock out the grip a little but less than an Officers Model Mag.
Bob