I suggest you break the gun down and clean/lube it thoroughly! Mine was filthy and had a lot of "particles" sticking to the barrel and bolt assembly.
The next recommendation would be to cram those magazines with 30 rounds and let them sit. The magazine design and spring is flawed. The spring is too strong and seems to become more flexible after that spring is compressed for a few weeks.
Be sure to slap the magazine on your palm to seat the rounds all the way back. If they go in and don't seat all the way back they tend to not cycle into the breech when fired. I put in 30 rounds each and slapped the magazine after putting three or four rounds in the magazine. It DOES make a difference...loading these particular magazines is critical for the gun to function. They seem to "loosen up" after some time and use, and the failure to fire is reduced or eliminated.
After cleaning it I went to the range and put about 100 rds through it. I shot a mix of ammo including 30gr Hornady Vmax, Winchester 36gr holow points and Gameshock 40gr.
As I expected the 40gr ran flawlessly. The other two had 2-3 fte's each.
I also had some mag related issues which I am sure were just new mag syndrome common to the mag itself.
Might have helped if I had loaded them up for a day prior to using them but that was my fault. I will take some worn in mags for my PMR with me next time and see what happens.
So far the only thing I DO NOT like is the charging handles. They are sitting right where I want to comfortably place my fingers. I tried an AFG2 and it helped a little but I might try a stubby pistol grip next.