Anyone ever see this on a firing pin before?

[HelloLarry]

I think the corrosion on the FP is where it bears against the carrier. Fouling collects there and corrodes the FP.

[joeyjoe]

Well, i have 2 bcm bolts that have less than 500 rounds through them and they both have lugs that display similar wear to the bolt you posted. Conversely, i have another bcm bolt and a colt bolt, both with quite a few more rounds through them than the formerly mentioned bolts and the finish on those is not worn off. Im not sure what is going on with that. like you, I was surprised to see the finish go so quickly on the lugs. However, I've had no functional issues with the two bolts in question so i rock on. Regarding the firing pin, if that is a ring/groove carved into the collar, I've never seen anything like it.

[pag23]

I checked my BCM bolt and I have some slight wear to the lugs at about 400 rounds but I haven't had any function or extraction issues either...my firing pin has a little ring of carbon but no groove... It is regular mid length as well.

[Runningman]

That (top pic) looks like the carrier has an improperly or non machined counter bore. Carrier should have a counter bore bigger than the firing pin flange where it seats. I would be scoping out this area.