Feed issues - Stern Defense MAG-AD9 AR-15 Glock 9mm/.40 Magazine Conversion Adapter

While it is well built, I could not get HP or flat tip rounds to feed without lots of jams. And the jam is actually within the adapter itself. The small feed ramp it has built in it has a very sharp edge on the bottom. I tried three different brands of glock mags. All would every so often do the same thing. Either the front edge of the bullet or sometimes the edge of the brass would catch on that sharp edge. It’s so sharp it will cut into the bullet or brass, depending on where it catches, and it will gouge into it and stop. Even using only fmj round nose, occasionally the brass edge would still jam. I tried everything I could think of on two range trips, but it was frustrating to say the least. If I have to limit myself to only fmj round nose Bullets and crimp the edge of the brass so much it folds into the bullet to make something feed, it’s a useless product. If I can’t figure something out, I’ll be returning mine.