Tavor TAR-21 and Magpul P-Mag compatibility
Now there’s some discussion over whether this is a real phenomenon or not. From what I could see, on my rifle, it seems quite likely that the rear profile of the polymer magpul p-mag is touching the bolt hold open device just enough to raise it and have it interact with the bolt even when the magazine has rounds in it.
I believe this to be the source of the jams and failure to feeds I experienced previously.