They all laughed - Pro Mag AR-15 / M16 9MM Magazine Adapter Block For Colt 9mm SMG Magazines, Quick Change

They all laughed!... " you're using the Pro Mag Block?"... Well, let me tell ya, this 9mm well block is performing flawlessly. The new design installed in a snap and all my mags fit perfectly. I've been using this build for Static Steel, IDPA and USPSA matches and general loads tests and haven't had one failure due to the Pro Mag Block. So, if you're looking for an inexpensive way to convert YOUR AR to 9mm, I very highly recommend purchasing the Pro Mag 9mm Magazine Well Adapter! One note.... depending on your bolt purchase, you may have to shave a little off the top and sides of the ejector. Big Deal... buy it, you won't regret it!