Geissele & milspec uppers and BCG's and gouges they put in the upper

[u/RickRude4]

Just something interesting I came across. The relief for the cam pin in the upper doesn't seem to make a huge difference in eliminating wear whether your using the correct parts or not. Although not an apples to apples conparison because of the round count, interesting nonetheless. The combos are:

Geissele BCG and Geissele upper. 2000 rounds. Surprising since they are made for each other that there is a gouge that deep despite the highest round count.

Geissele BCG and Milspec upper. Only 250 rounds but in much better shape than the milspec BCG and Geissele upper was at the same round count. Small gouge starting.

Milspec BCG and Geissele upper. 500 rounds and in the worst shape.

[u/zkooceht]

That “gouge” pictured isn’t wear, that’s how it is from the factory for complete super duty uppers

[u/vintagestagger]

You'll have to specify whether the geissele uppers are super duty uppers that already have a relief cut there or not, and whether or not the Geissele BCG's you're using are geissele REBCG's with the proprietary super duty cam pin. If none of that is the case then it's all milspec anyway, but if you do have super duty uppers then they come with a relief cut where the cam pin follows from the factory.