Doesn't fit properly. - FAB Defense M16/AR15/M4 Ejection Port Cover

The circumference of the hole where the hinge pin goes is so thick, it inhibits the cover from swinging open properly. It creates a bind on the pin and is tight up against the receiver. I suppose if you sand it down it would work but I would be worried that will lose strength and probably break. There are better options out there in my opinion.