You know, that part of the barrel when you look down into the muzzle, into the muzzle brake. Mine is obviously dirty, and q-tips arent cuting it. Is this a place that shoud remain "dirty"?

This is how I do it. Take a q Tip and put Hoppes or solvenbt on it and hit the area you wenat to clean. Let sit. Then if your annal you can buy a set of dental picks for $5 at Harbor freight and get down there to gentlty wipe/scrap the area. Or you can cut a wire clothes hanger and take a hammer and beat the tip till its flat and get the angle you want and do the same thing. I just hit it with a Q tip with solvent (Hoppes) and then wipe off and then clp lightly. It don't have to be spotless. But everyone is different. Cheers WarDawg

I don’t worry about it.

If I did, I’d probably apply a carbon solvent such as Blue Wonder, let it soak, and then clean it off with Q-tips.  I suspect it would take several applications to make a dent in the carbon.

If you try this, be sure and re-oil everything afterwards to prevent rust.

Another possibility is letting it soak in Kroil (which is basically a penetrating oil).

DO NOT EVER put any hard object against that portion and scrape it.  That is the last portion of the barrell that the round contacts and putting a burr or gouge there can really fuck up a barrell.  Carbon does not cause rust or any other type of corrosion.  Carbon does gum up moving parts if there's too much since there are no moving parts just leave it alone.  Remember you don't run a cleaning rod against bullet direction whenever possible for this exact reason you do not want to damage that crown.  I don't care what the DS in basic said 'cuz most of 'em are not gun guys.  Just leave it dirty.

I personally would just leave it alone and clean with hoppes and clp, but taking a dental pick and getting to that area ain't going to hurt anything.There not made of butter. Think about the millions of GI's ramming a USGI cleaning kit down the pipe.Section after section hitting the muzzel from Joe Pvt.(Im not saying thats good either).We couldn't turn our M16's in until spotless. That area couldn't have any carbon on it. The amoror would make cleaning picks for the platoons. Now is all this over KILL? You bet.I dont' clean mine spotless anymore .Its clean (pratical) clean.If Hopes # 9 won't get it off, It's meant to be there, WD

carbon doesnt cause corrosion huh? now i've heard it all. carbon is extremely corrosive to aluminum and titanium.

Well, I'm not sure about titanium but I'm pretty sure carbon does not "cause" corrosion of aluminum or steel.  Carbon CAN trap/absorb moisture which can cause rust/corrosion.

The barrel and FS/Brake are steel parts.

Carbon and aluminum may be galvanically corrosive, but most aluminum is anodized, making it a non-issue.