Very well made but doesn't fit bcm upper - Jacob Grey Firearms Billet Dust Cover

This is an attractive ejection port cover made from thick, well machined billet aluminum with a classy matt finish that in my opinion offers an aesthetic upgrade over the thin pressed metal stock covers that corrode so easily.

However it did not come close to fitting on my Bravo Company Manufacturing AR-15/M4 Upper Receiver (BCM4-UR-M4). The left side from the mid point up around the curve will not clear the forward assist channel on the upper receiver. It is not just a tiny bit of filing needed, I estimate that about 1/32" of material removal and reshaping is needed on the left side of the cover.

I do not know if the incompatibility is the cover itself, the BCM upper or my lack knowledge about the parts I selected. I'm going give the Strike Industries polymer cover a try. The polymer can easily be reshaped a little if needed without having to refinish the filed area.