It worked first time - Pro Mag AR-15 / M16 9MM Magazine Adapter Block For Colt 9mm SMG Magazines, Quick Change

I was looking for a low budget 9 mm AR build. Thought I would try this mag insert. I didn't know or realize that it was made by Mag Pro and it was plastic. I have had some issues with Pro Mag products in the past. Well, opened up the package and read the instructions. Tried to insert it into my Moreen Firearms lower. Wouldn't fit mag well was abut .002 to small in diameter. Tried it in a Anderson lower and went right in. After the AR9 was complete went to the range to see how it would cycle. I was concerned a little about the ramp and the distance the round was from the chamber. After 3 rounds it jammed. Stove piped the round. Cleared it ran more rounds and once again stove piped a round. Then I realized that the rounds that were jamming were flat tipped rounds. All my round nose reloads cycled perfectly. I must say, Pro Mag, plastic, Colt mag and round nose reloads combos, everything works perfectly.