removing rock hard ar15 foulling

[brentn]

I have seen the bolt-scraper tool and watched a video on its use, looks like a fantastic way to get the really really hard stuff out from inside the bolt, as chemicals don't seem to be able to touch it.
For those that don't know, the following in some areas of the weapon becomes so concentrated that it leaves a layer that you have to literally scrape off, the substance is very similar to the lead inside a wood pencil. Its very hard and does not soak up chemicals to help break it down.
The edge of the bolt on the rifle near the gas seal becomes very 'caked' with it, and I must have spent a freaking hour with a bronze brush and clp to try and break it down...
In the end I took a razor blade and scraped away at it, mm by mm, took forever and theres still a little on it.

However, after removing the compensator and cleaning up the crown, I was presented with the same problem. The crown is so coated that I'm afraid that accuracy could be affected.
I tried scraping the crown off with the razor blade of the caked on deposits, but its taking way to long.

Does anyone know whats the best way to remove this?
Is it becuase of the compensator that it became so caked on? had i removed the comp would the deposits been much much less?

Any input is appreciated.

Brent

 

[Gord]

On the forum list view, this shows up as simply "removing rock hard AR-15."

I clicked wth some trepidation.

If you have a Dremel or a drill, try chucking a wire wheel attachment into it, maybe? I get carbon buildup on the crown of my .22 that's almost impossible to get off with anything other than a knife. Not sure whether a wheel might damage your crown, though...

 

[rangerruck]

try soaking parts in brake cleaner for a few days. then brush off. if this doesn't work, try Sweetshooters, a super astringent, leave it soaking for a few days.
should come right off. If this doesn't work, there is a metal parts cleaner chemcal, they sell at Autozone parts stores, that is sold in a solid steel gallon container, with a safety strap/pressure strap around the top. Sound scary?
good, because it is the most volatile cleaning compound that i have ever used, you better wear gloves, and goggles, and if something has paint on it, that paint is coming off. period.

 

[dmftoy1]

I bought one of those tools for the inside of the bolt carrier and they work pretty good. (Brownells) It's not perfect but it definately is the best thing I've found for getting in that area. If I use a thin patch I can even wrap it around the scraper to get a it a little bit cleaner.

I've never really had any problem getting it off of the bolt itself. It takes a bit of scrubbing but a coarse linen patch and some hoppe's #9 and I'm usually able to get it off. (I tend to wrap a patch around the area and just spin the bolt with my fingers while holding it tight with the other hand)

Now if I've put say 500-600 rounds through it without cleaning it then it might take me a bit longer. A typical range session for me with an AR is 30-60 rounds, and I probably clean the bolt every 3rd range session.

Regards,
Dave

 

[Walkalong]

Slip 2000 Carbon Killer. It really works.

 

[Redhat]

Fellas,

To clean the bolt tail, take the borebrush and try scraping the carbon off with the threaded end. Takes about 1 min.

 

[Bartholomew Roberts]

Another vote for Slip 2000 Carbon Cutter or their 725 Degreaser. Both do an excellent job in cutting through built up carbon fouling; but you probably want to go with the Carbon Cutter for the really hard build up on the tail of the bolt.

Second, the areas you are cleaning really don't need cleaning and are basically self limiting on their carbon build up.* The carbon build up on the crown happens because of the compensator attached. If you remove the compensator, soak it in carbon cutter and then just fire a few shots, that will blow most of the carbon off. On the other hand, I never cleaned the crown of my barrel under my A2 comp (10k rounds) and if it cost me accuracy, I didn't notice it.

* There is actually some debate on this. Well-respected trainers like Pat Rogers have stated that they have never had a problem with carbon build up here and these are guys that see a lot of rifles. On the other side, DPMS President Randy Lutz has stated that this can cause malfunctions and that they have seen carbon build-up cause this. My experience mirrors Pat Rogers (which isn't suprising since I fire a lot less often). I think a safe conclusion to reach is it will take a LOT of firing before carbon build up here becomes an issue.

 

[Howard Roark]

Another testimonial here on the Slip 2000 products. I use the Gas Piston Parts / Choke Tube Cleaner on my ARs. I've said it before, Throw away the scrapers and soak it in Slip 2000. The carbon really just wipes off.

 

[taliv]

Second, the areas you are cleaning really don't need cleaning and are basically self limiting on their carbon build up.* The carbon build up on the crown happens because of the compensator attached. If you remove the compensator, soak it in carbon cutter and then just fire a few shots, that will blow most of the carbon off. On the other hand, I never cleaned the crown of my barrel under my A2 comp (10k rounds) and if it cost me accuracy, I didn't notice it.

same here. I have 3 AR BCGs with more than 5000 rnds now, and another one getting close, and I've never actually cleaned that part. I mean, when I clean the bolt, I occasionally scrape at it for a minute, realize what a PITA it is and stop.

I believe the theoretical problem it could cause is when a big chuck of carbon flakes off, it could land somewhere like the trigger group, and cause a stoppage.

 

[nicholst55]

Distilled white vinegar and a Scotch-Brite pad works wonders, and costs a small fraction of what Slip 2000 costs.

It works for me.

 

[brentn]

Wicked advise guys, thank you.

Going to try the vinegar and see how it fairs, because I have it right now. If that doesn't work I'll order the carbon cleaner mentioned above.
Will have to try the threaded end of the brush on the tail, interesting idea.

Btw, I also soaked the bolt and carrier in brake cleaner for 24 hours, it did absolutley nothing for the hard fouling. Although Every bit of loose residue and oil was absolutley gone

 

[Pat_Rogers]

There is absolutely no reason to clean this. Dean Caputo. a Colt Armorer Instructor, who also teaches an excellent Carbine Diagnostics class, states emphatically that there is no viable reason to clean it, and that people using scrapers etc usually wind up damaging the bolt rings.
I put a few rounds downrange a year. I supervise a lot more rounds being fired by others.
I've heard the stories about carbon causing corrosian, but here again, we shoot guns, not have them sit in racks. I have also heard about carbon breaking off and winding up someplace. I'll file that away with the myth of staggering the bolt rings.
I don't clean the bolt tail on my guns- not ever. What you do is of course is up to you, and Slip 2000 EWL is what i use for lubrication and Slip 725 is what i use as a cleaning fluid.
Enjoy!

 

[W.E.G.]

I bought a Brownells tool to scrape the inside of the carrier. I don't think it works very well because it doesn't get the carbon on the sides of the inside of the carrier. It only gets the bottom inside area of the carrier. I have much better success with screwdriver. I can reach all areas where the carbon accumulates. I'm sure I don't get 100% of it, but I probably get a solid 90%. I only spend about a minute scraping with the screwdriver. I've developed a feel for when I'm engaged on the carbon, so I don't even have to look into the carrier while I'm scraping. When I'm done scraping, I hose the inside of the carrier with Break-Free to prevent corrosion, then I wipe off the excess. I've been doing this for years on the same rifle, and its still a tack-driver.

As for the tail of the bolt, My nephew neglected this area once on one of his rifles. The rifle was otherwise cleaned, but the bolt carrier was neglected. The rifle was stored for several months. I inspected the rifle before firing it, and I discovered severe rust where the carbon accumulated on the tail of the bolt. I scraped-off all the rust and carbon. The bolt still worked fine, but it bugged me that this happened. There was visibile pitting on the area where the rust formed. Now, I just use a utility knife (the cheap kind with the retractable blade) to scrape the accumulation off the tail of the bolt. I can get 98% of the carbon off the tail of the bolt in one minute's work. The bolt gets hosed with Break-Free too before reassembly. No problems with rust there anymore.

I don't tamper with the carbon accumulation near the muzzle. That area gets hosed with Break Free too. So, no rust problems. The blast of the gas escaping the muzzle behind the bullet keeps the part of muzzle that matters from accumulating any problematic carbon.

 

[jobu07]

If you absolutely have to get it out of there, dental picks are your friend. Works wonders when that M16 has to be "inspection ready."

 

[Bartholomew Roberts]

W.E.G. - I just put the CLP/Slip 2000 over the top of the carbon on the tail when I lube the bolt. No rust and it seems to keep the carbon loose enough that it never builds up past a certain point.