I appreciate all the feedback guys. PMags it is.
As far as the FTF goes, if I manually cycle the action, I can feed and eject a whole magazine. However, the gun is incapable of this. I suspect its the mags because when it hangs, the round gets hung in the mag. It starts to feed but doesn't actually get stripped off and ends up cocked in between the chamber and the mag.
That said, I'm gonna start with new mags as its a known issue. If it persists, I'll start looking at headspace and timing and all that other fun stuff I know nothing about.