Buffer face wear - not pin related?

[dont_tread_on_me]

I emailed Geissele and received a reply that essentially it was a discrepancy between BCG hardness and buffer.

[vicious_cb]

I emailed Geissele and received a reply that essentially it was a discrepancy between BCG hardness and buffer.

That is some crap right there, from the uneven wear it looks like there's a pretty sharp burr on the inner radius of the carrier. I would pay very close attention to the machining on the buffer retaining pin channel of the carrier by running your finger and feeling for any sharpness. From there you can just knock it down with a file.

[DoubleW]

Wrong thread

[rifleman8]

I've run into this about 4 times over the years, and with "Tier 1" BCGs. Tiny little tit burrs - associated with the retaining pin channel machining on the carrier tail as Vicious mentioned. And as Markm pointed out the buffer is rotating while being pushed up tight against the ass end of carrier, so a tiny steel burr will leave dramatic looking gouges in aluminum buffer face. Kinda like when you spill a small spoonful worth of oil on the garage floor and a minute latter it looks like you dumped a whole quart. When working with a carrier for the first time I just assume it has burrs and proceed accordingly.