I have found the same thing with my colt style lower and flat nose bullets. With RMR 124 truncated flat points its about 98% reliable. The first round will sometimes nose up and hits the top of the barrel face and stops it cold. You also need to be sure to let the bolt go closed under spring force and not ride it forward or the round can fall out of the feed lips. Once I figured these two things out its been 100% reliable with round nose bullets. I expect most defensive hp's would work fine since they are basically round nose profile with a hole in the end but I haven't tried any. The one bullet I found that would absolutely not work is a berry's 124 target HP. Thats not surprising though as they are practiacally wadcutters and they don't feed in 3 of my pistols either. My highpoint 995 was actually more picky on bullets than this is.
I still prefer the colt mags because they are much easier to load, don't look goofy, and parts are fairly universal, so I would make the same decision again.
