LMT MWSE bolt & bolt carrier deposits

[JimGnitecki]

I find my LMT MWSE components reasonably easy to clean, except for 2 places on the bolt and on the bolt carrier. You can see the black carbon-like deposits on the "tulip-shaped" surface of the rear of the bolt, right near the rings, and also at the bottom of the deep recess in the bolt carrier:

Although MPro7 cleaner cleans everything else off of every other component, it does not dissolve these 2 deposits:

I have been using white lithium grease as my bolt and bolt carrier lubricant, and speculate that these deposits come from the grease being burned in this area where the bolt carrier and bolt are subjected to the hot gases from the barrel.

I have been afraid to use mechanical methods to "scrape" these off, thinking they would damage the surfaces of the bolt and carrier.

Are they a problem being there, or is this "normal" for a direct impingement AR rifle?

If they should be removed, how do you do it without damaging the metal and the very nearby gas rings?

Should I abandon the white lithium grease for the application, and simply use my other lubricant, Militec-1, for the bolt and carrier?

The rifle functions flawlessly by the way. Never a single problem. And, last weekend, it fired a 3-shot group, with Federal Gold medal factory ammo, that measured 0.28 inch center-to-center.

Jim G

 

[vinsonr]

Re: LMT MWSE bolt & bolt carrier deposits

I use dental picks to scrape my bolt, specifically in the area you are talking about. However, the deposits aren't anything to worry about really. I would just clean is as best you can and not be overly concerned. I think I have a bolt that's fouled up like that and it does not want to come off either.

 

[Shooter45]

Re: LMT MWSE bolt & bolt carrier deposits

This is a common area to accumulate carbon deposits on direct impingement systems. You will always find this area with deposits no matter what caliber or maker if they are an "AR" type. I use a chamber/bore brush to scrape off the back of the bolt and use a dental pick, as mentioned previously, for the inside of the carrier. Any contact by brushing, rubbing, or scraping off the carbon will not damage it.

 

[Oakland Tactical]

Re: LMT MWSE bolt & bolt carrier deposits

Here is a way to do it. 308 bolt carrier cleaner I use a knife on the back of the bolt <span style="font-weight: bold">BE CAREFUL</span> and the brownells screwdriver type of carrier cleaner to get most of it off of the inside then Ill stuff some steel wool in it and use to tool to get where it didnt make contact the first time. It doesn't have to be perfect.

 

[JimGnitecki]

Re: LMT MWSE bolt & bolt carrier deposits

That CRT-25 tools at Brownell's seems like a good fast safe method. A little expensive ($50 plus shippnig for the AR-25 version), but looks like it woul work well.

Jim G

 

[JimGnitecki]

Re: LMT MWSE bolt & bolt carrier deposits

Found the CRT-25 (308 version of CRT-15) lowest price at Fulton Armory for $39.95 plus $10 shipping, for anyone else interested.

Jim G

 

[Ballista One]

Re: LMT MWSE bolt & bolt carrier deposits

The carbon that builds up on the tail of the bolt is normal and doesn't affect operation. Keep in mind when scraping the tail with a tool, not to scrape the area that rides in the carrier. It creates half of the seal for the terminus end of the gas system.

 

[JimGnitecki]

Re: LMT MWSE bolt & bolt carrier deposits

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m_gale</div><div class="ubbcode-body">Keep in mind when scraping the tail with a tool, not to scrape the area that rides in the carrier. It creates half of the seal for the terminus end of the gas system. </div></div>

yes, I thought that is the case. I even hesitate to get too agressicve on the non-sealing surfaces, for fear of creating gouges in them that could promote even worse carbon buildups.

Jim G

 

[Dynamic Response]

Re: LMT MWSE bolt & bolt carrier deposits

My LMT is the same. The whole gun is damn near spot less except those 2 spots. I just spray it with cleaner and let it soak while I clean the barrel. Then wipe as much off as possible and scrape the rest with a tiny screw driver or Hard plastic pick then it comes right off.