Well, I have narrowed down the failure to fire as a failure to load from the mag. And I have further narrowed it to a specific pmag 20 rounder, so I am no longer worried about that.
I went out last night and got through about 150 rounds, and when using the one good pmag I have, I had exactly one malfunction, a failure to eject.
If I'm not mistaken, this may be a gas setting issue? I had the gas set to 3, and the rifle is dirty. I am shooting brown bear.
My understanding is that I should be able to relieve this problem of FTE with either a cleaning, or turning up the gas. Is this a reasonable understanding?
I'm gonna turn up the gas to 4 and go through 200 more rounds this weekend.
I will say this: I love this gun. I mounted the EOTech and Vortex 3x magnifier before yesterday's session, dialed in the EOTech with a bore laser, and shot some nice groups around the bull (at short range, I was at an indoor range). I can't shoot well enough to tell if it is properly dialed in, as there was not a bench shooting option at the range, but it seemed close, and target acquisition was fast with the eotech, even with the magnifier. This gun is way more fun than the AK-47 that dragged me into this hobby.