Chamfering Buckmark chamber?

[Usmc0844spare]

My Buckmark has smears of lead all over the breech and bolt faces after range trips.

Best guess is some lead is getting shaved off bullets on chambering and then getting pounded flat.

IF I determine this is the case, and want to lightly chamfer the chamber edge... is this remotely DIY?

[divingin]

Assuming you can get the barrel off to access it and center a tool on the chamber, I don't see why not.

That said, you only want to lessen the sharp edge of the chamber, not really chamfer or radius it to any degree. .22LR brass is thin, and you'll be reducing the support the cartridge has when chambered (not to mention reducing the pinch area of the firing pin.)

Before doing that, I'd investigate exactly what is causing the lead to shave.

[Usmc0844spare]

Assuming you can get the barrel off to access it and center a tool on the chamber, I don't see why not.

That said, you only want to lessen the sharp edge of the chamber, not really chamfer or radius it to any degree. .22LR brass is thin, and you'll be reducing the support the cartridge has when chambered (not to mention reducing the pinch area of the firing pin.)

Before doing that, I'd investigate exactly what is causing the lead to shave.

Yeah, alternate theory is that the bit of the slide that pushes rounds into the chamber is scraping lead off the next round down in the magazine.

Need to do some experiments next time I'm at the range.

[ar15barrels]

I would not do any re-shaping.
I would go after all the sharp edges with cratex and polish all feed surfaces as well as inside the mag lips.

[kendog4570]

Try tweaking the mag lips or a different magazine first. If you screw it up you can always get another mag. .22 chamber metal put-backers are hard to come by. Even more scarce than a hole-smaller. ;-)

[newbie1234]

I would not do any re-shaping.
I would go after all the sharp edges with cratex and polish all feed surfaces as well as inside the mag lips.

This ^^^ and try the brass plated ammo.

[c good]

My Buckmark does the same. I'm not sure it's lead though. I think it's a combination of the copper wash and parafin that loads up on the breach and bolt face. It has never affected performance. I just put a small patch soaked with Hoppes 9 and let it sit for a few minutes then scrub with a toothbrush. Cleans up nice. Had this Buckmark for 20 plus years. One of my favorites.