View Full Version : Is this excess carbon buildup on my AR bolt?

04-24-2008, 7:28 PM
Can't seem to get it off even scrubbing with a brass brush. I'm curious if this is considered a lot of buildup. I've also heard this buildup might help in gas seals but I'm unsure.



04-24-2008, 7:29 PM
looks like mine

but i shoot lots of wolf

if it aint broke leave it be

make sure you stagger your piston ring gaps

04-24-2008, 7:33 PM
This was after about 300-430 rounds of M193 Privi with one cleaning in between.

04-24-2008, 7:35 PM
That's normal. You can use some cheap $1.99 knife to scrape it off it really bothers you...you can also just leave it alone and your AR will still be fine. I've never seen it build up past a certain point even after a couple thousand rounds.

Also, the rings don't need to be staggered. Several people have purposely lined up their rings and shot their AR's and it worked fine every time...but who know, maybe they were lucky. :) I don't bother staggering mine.

04-24-2008, 7:40 PM
Okie Dokie, thanks guys.

04-24-2008, 7:56 PM
thats pretty bad but im use to military cleaning use a dental pic and dont be afraid to push hard and itll chip right off

04-24-2008, 8:02 PM
I am pretty anal when it comes to that.. I just remove it every time after I get home from the range with a Razor Blade...

04-24-2008, 8:02 PM
yeah, i would have gotten my *** chewed off if my m4's bolt looked like that. but that was the army's way of keeping us busy until the next formation. :rolleyes:
but now i keep my bolts and chambers the same way... no buildup whatsoever...

04-24-2008, 8:20 PM
Carbon on the bolt tail is self limiting so dont worry about it. If you are obsessive compulsive soak the bolt in carbon solvent.

Blacktail 8541
04-24-2008, 8:37 PM
Not a problem at all unless you have been indoctronated to military clean!

04-24-2008, 8:40 PM
I shoot Privi and get that. I clean it off with a dental pick.

Bushmaster Manual syas to make sure your gas rings are not lined up. It would probably be a fluke if they happened too anyway.

Mike 56
04-24-2008, 8:46 PM
I used to use a empty shell case i smashed in a vice and sharpen it with a file. Now i have a real fine brass wire wheel on my grinder cleans Ar bolts and AK gas pistons right up.


04-24-2008, 8:56 PM
also if ur into high speed cleaning tricks put some sand in ur hand place bolt on sand/hand close hand rotate bolt

04-24-2008, 9:21 PM
wow. . .burly buildup there. . .

But then again, .mil guy here. I would be pushing mother earth into a new orbit if my old DI ever saw that much buildup on my bolt!

04-24-2008, 9:25 PM
Yes, that's excessive build up. It won't clean itself. You need to scrape it off with a tool.

04-24-2008, 9:37 PM
I used the end of a A-zoom snap cap to get some of the really cruddy stuff off.

Seems to be quite a gamut of response here. Some think it's terrible, some think it's ok and normal.

I've heard that the build can help make better gas seals... is that true?

04-24-2008, 9:54 PM
That's what mine looks like when I bought it used. Now it's clean as new and was getting cleaner and cleaner every time out, even shooting Wolf. I followed my brother's advice to use the firing pin to scrap the gunk off like he learned in the Army. Works great and no, it doesn't damage the firing pin.

04-24-2008, 9:55 PM
Its quite improbable that enough carbon would build up in the bolt tail to induce a stoppage.

04-24-2008, 10:02 PM
I just remove it every time after I get home from the range with a Razor Blade...


There's a song about that by King Missle...

04-24-2008, 10:04 PM
I'm curious if this is considered a lot of buildup.

Don't worry about it.
Just keep shooting.