Works but last round bolt hold open tab broke - Pro Mag AR-15 / M16 9MM Magazine Adapter Block For Colt 9mm SMG Magazines, Quick Change

If you are building a PCC and starting from scratch, I would recommend using a dedicated AR9 lower. But if you have a AR15 lower and looking to build a 9mm PCC this will work but you get what you pay for. The LRBHO tab broke after 1st spent magazine. I ran about 140 rounds thru with no failure to feed or other catastrophic issues, using round nose FMJ. Colt metal metalform mag catches and releases with no issues. Works good for the price