I just got a new BCM BCG and was taking it apart to clean. After I was done, I was using a brass punch to push the extractor pin back into place when I slipped and it scratched the bolt. The scratch is not deep enough to have damaged the metal, but it did remove all the finish down to the bare metal along the scratch. Will the bolt rust there now? Should I get one of those Birchwood Casey Black pens or is it no big deal and I should not worry at all?
You really scratched a heat treated steel bolt with a brass punch? Take some solvent to the bolt, scrub with a stiff bristled brush and report back.
I don’t believe I scratched the metal, but I removed the finish on that section. I’ll try your suggestion to see if it is just brass residue and report back shortly.
I tired that. The finish is definitely scratched. I know I didn’t damage the steel. I’m just worried if I just opened up a window for rust down the road.
Meh. Shoot it & worry not.
The finish will come off in a lot more places once you start shooting it, better put it back to the safe and not use it. 
try to pretend you arent a nancy boy and just shoot it.
This is silly, fellas.
You have no worries. Besides, you shouldn’t need a punch to take out the extractor pin. I’ve always used the weapon mounted pin removal tool–the firing pin. No tapping, etc., just used to push it out.
This is TOS! :rolleyes:
And why would you need a punch to put the extractor pin back in?
On every one of my guns I can do this with my fingers.
And like Mark5 says… the firing pin is the removal tool.
Yes, forgot that part-just fingers and a push
The finish will come off in a lot more places once you start shooting it, better put it back to the safe and not use it.
I was going to say this. I suspect that you won’t even see the “scratch” after a few thousand rounds. Go shooting, have fun.