AR Sponsor
Tips for cleaning star chamber? (Page 1 of 2)
Posted: 11/12/2025 8:14:37 AM EDT
[Last Edit: Fooboy][Edited]
|
BCG doesn't want to go all the way into battery If I'm cycling it slowly into battery with charging handle. BCG is pretty clean and does the same thing with other bolt carriers I tried. (Barrel is DD and BCGs are DD). I think I need to clean the lugs of the receiver a bit from suppressed shooting. It's just strange because my other guns (also DD barrels and DD BCGs) are way dirtier but slide into battery with ease no matter how gingerly I do it. Any tips or tools to clean this most effectively/efficiently - or other areas to investigate? |
Isaiah 1:18 - "Come now, let us reason together," says the LORD: "though your sins are like scarlet, they shall be as white as snow"
 
|
In God we trust, all others pay cash
| Just use a wet chamber brush to loosen up any crud followed by whatever mop you can attach to a cleaning rod, spin buy hand and change until its no longer coming out filthy. I like to use old t-shirts, stick in and twist, find a clean spot on the shirt, reinsert and twist, and repeat until its clean enough for you or your armorer. |
|
Originally Posted By Fooboy: BCG doesn't want to go all the way into battery If I'm cycling it slowly into battery with charging handle. BCG is pretty clean and does the same thing with other bolt carriers I tried. (Barrel is DD and BCGs are DD). I think I need to clean the lugs of the receiver a bit from suppressed shooting. It's just strange because my other guns (also DD barrels and DD BCGs) are way dirtier but slide into battery with ease no matter how gingerly I do it. Any tips or tools to clean this most effectively/efficiently - or other areas to investigate?  !Have you tried a small wire tooth brush sized brush and like dental picks and hook picks to loosen get at any Carbon? Hows it do if you clean it, lube it well, work it a few times, then pull the CH back and let the spring send it home into battery? Don't ride it. Pics of BCG and Chanmber? |
LARUEMINATI
NRA Endowment Life Member
Originally Posted By Boom_Stick:
""AKs are for villagers you have to tell not to shit in their water supply.""
NRA Endowment Life Member
Originally Posted By Boom_Stick:
""AKs are for villagers you have to tell not to shit in their water supply.""
|
When you ride the charging handle forward what is happening is the bcg gas key is aligning with the gas tube. So there is some friction when it happens. Also the gas rings that are on the bolt tail will make it difficult to close just a little if you do it slow enough. Also the hammer on the lower should make it a tad bit difficult to ride the bcg home. You’re more likely feeling the combination all three of these things acting when you do it slow enough. Thus why they say don’t ride the handle. What should happen is if you took the bolt off and simply put the naked carrier into the upper without a charging handle and with the dust cover opened and tilted it about 45 degrees the carrier should fall fully seated and should unlock when you do the opposite rotation. If the gas tube is misaligned it should have difficulties falling in with a naked carrier. The bolt having strong positive friction is a good sign when assembled into the carrier. If you can fully assemble the bcg and attempt the same 45 degrees gravity test the bcg should not fully seat on its own. It should have a bit of force going into battery which means the rings are going to seal gas during fire. When fully seated and you put the upper 90 degrees it should require a bit of a wiggle for it to undo. Also if there is something THAT dirty in the start chamber you’d see it as opposed to having to clean it. |
|
I just use the GI style chamber brush. I think some might just pull it back and forth but it is supposed to be rotated also to clean the lug area. Then I stick a 3" patch in there and move it around in the lug area with a tool to get the goop out. I follow that with a patch with some clp. The GI rod makes a T handle you can rotate if you leave the handle straight with its rod and put another piece of rod through the hole in the handle. |
|
Originally Posted By Tejas1836: www.amazon.com/dp/B0BY7786JT Holy shit, this guy just cured cancer! C'mon if you do one thing to an AR besides lube is clean the chamber and locking lug recess with a CHAMBER brush. It's the heart of the gun, plain and simple. |
|
Originally Posted By dalle0001: ...the gas rings... This is my bet. When shooting some dirty ammo the bolt will be actually difficult to slide in and out of the carrier by hand until I clean it and the bore of the carrier. With the rifle open, I have to really push on the back end of the bcg to get the lugs to lock into the extension until I clean it. |
|
Disassemble the BCG, spray it all with CLP of whatever flavor, brush with AP brush...assemble...test gas rings for hold. Spray chamber and barrel with CLP, brush chamber by spinning the USGI chamber brush, bore with rod and brush...pull a bore snake through it...swab out chamber and barrel extension... Done. |
|
Never used a star-shaped brush, and I shoot almost exclusively suppressed. Prop the upper muzzle-down in the trash can, spray barrel extension and bore with brake cleaner, let it sit, hit it once more, cotton swabs in the lug recesses, clean bore as-normal. |
"What is socialism? The most difficult and tortuous way to progress from capitalism to capitalism." -Stated at an intel conference, East Berlin, Oct. 1988
"Every election is a sort of advance auction sale of stolen goods." -H.L. Mencken
"Every election is a sort of advance auction sale of stolen goods." -H.L. Mencken
https://wilsoncombat.com/cleaning-tool-upper-wilson-combat-2-pads.html  AR Cleaning Tool from Wilson Combat |
Tom Sawyer.
"If The Rules brought us to this, what use are they?"
"If The Rules brought us to this, what use are they?"
|
Originally Posted By tortilla-flats: https://wilsoncombat.com/cleaning-tool-upper-wilson-combat-2-pads.html  https://www.youtube.com/watch?v=tryb9li7gAsthat's not gonna clean . . . . . . "the star chamber" 
|
Joined:
Nov 2025
Posts:
5
EE: 0% (0)
PA, USA
|
Originally Posted By Colt653: yep I've been playing with M16/AR15 rifles for decades, never heard the barrel extension called a "star chamber" https://m.media-amazon.com/images/I/61jJNslG2yL._AC_SL1500_.jpg Ive been hearing it in the Army for about a decade, makes me wanna start saying "clip" and "carry strap". If you dont need the gun "Army clean" just wipe it and keep the bolt wet. No need to brush or scrub anything until its shiney or spotless. |
|
Originally Posted By FrankW134: Ive been hearing it in the Army for about a decade, makes me wanna start saying "clip" and "carry strap". If you dont need the gun "Army clean" just wipe it and keep the bolt wet. No need to brush or scrub anything until its shiney or spotless. Yes, and and it is VERY annoying. But FWIW........... it is a "CARRY STRAP" in some of the FM's. |
Joined:
Mar 2025
Posts:
524
EE: 0% (0)
FL, USA
|
Originally Posted By Fooboy: Any tips or tools to clean this most effectively/efficiently - or other areas to investigate? Get a cheap set of segmented cleaning rods. A GI issue or a Hoppe’s will do. Get a nylon chamber brush. Pick up your battery operated drill, preferably one with a light. Fit the cleaning rod into the drill, tighter than illegal pussy. Dip the tip into solvent. Force it in, oh yeah, oh yeah… Then start the drill. Do it slowly, ramping it up until it is grinding along at about 200 RPM. Drill baby, drill for about thirty seconds, then stop and pull it out. Spray with solvent. Clean with a .410 mop. Repeat. If you are feeling froggy, use some copper and lead solvent on the first iteration, but then do two goes with the standard solvent. Invest in some hemostats. You can get them at Hobby Lobby. Use them with paper towels soaked in copper/lead solvent. Cleaning isn’t just necessary, it is a compulsion that might save your life. Act accordingly. |
Joined:
Mar 2025
Posts:
525
EE: 0% (0)
FL, USA
|
Originally Posted By Fooboy: BCG doesn't want to go all the way into battery If I'm cycling it slowly into battery with charging handle. - or other areas to investigate? My LWRC wouldn't do fully close the bolt when I rode the charging handle. Never would even when brand new. I recently switched the factory buffer spring out for a Tubb Flat Wire spring, which has a lot more bolt closure force while keeping overall spring strength the same (flatwire effect). The bolt now closes completely and authoritatively no matter how slow I go. I've been very impressed. |
|
From the Canadian maintenance manual for the C7 rifles: The locking lugs are the most important area to keep clean on the weapon. Loose powder residue builds up in the recess in front of the lugs. This buildup may bind the bolt and prevent it from cycling smoothly. The loose residue in this area will eventually pack if not removed. One cause of buildup in the locking lugs is incorrect cleaning. |
|
Originally Posted By j3_: Sure I think it is something like rotate the chamber brush and clean it all out with a big patch. https://www.coltcanada.com/wp-content/uploads/2021/04/cleaning-instruction.pdf Originally Posted By j3_: Originally Posted By spydercomonkey: Do they have a recommended procedure? Sure I think it is something like rotate the chamber brush and clean it all out with a big patch. https://www.coltcanada.com/wp-content/uploads/2021/04/cleaning-instruction.pdf Excellent, thank you. They mention the chamber / locking lugs being the most important area to clean twice, so definitely buying a chamber brush now. |
|
What about THE TALON? I got one of these with the bolt tail scraper/carrier bore cleaner thing as a kit a few years ago. Honestly, it seems like it would only really be needed if there was a ton of buildup in there, but it certainly does work. |
|
Originally Posted By spydercomonkey: Is brake cleaner best applied before or after brushing? Or perhaps bore/after? Originally Posted By spydercomonkey: Originally Posted By TGWLDR: Proper chamber brush. Brake cleaner. Compressed air. EZPZ. Is brake cleaner best applied before or after brushing? Or perhaps bore/after? I clean with solvent as normal, use the brake cleaner to help loosen the shit that collects in the hard to reach areas. Compressed air will blast out what the cleaner dislodges. |
"All welchers should be removed from the EE".-Aimless
|
Originally Posted By Fooboy: Star chamber is preferred nomenclature, dude. Originally Posted By Fooboy: Originally Posted By Colt653: it's called BARREL EXTENSION If it inches some folks closer to an aneurysm, I'm gonna start using that more frequently. |
| The name "Star Chamber" always annoyed me, too. In the mil, we called it the barrel extension, and more specifically, the locking lug recess of the barrel extension. Pretty much my whole 20 years I used nothing but CLP on a chamber brush, followed by a GI rod t-handle section with an eyelet and a 7.62 patch to swab out the chamber and locking lug recess. I think my last couple of years in, my last unit bought a shitload of those felt star shaped swabs that we would push on the end of a 5.56 bore brush and turn by hand once it was in the recess. They would clean out most of the last bit of carbon/CLP slurry. Did it make a functional difference by swabbing the recess out with one of those felt swabs? Not that I could ever tell. |
RIP TSgt Jason Norton and SSgt Brian McElroy. KIA 22 Jan 06, near Taji, Iraq.
LaRue Armorer, Colt 1911 Armorer, Colt M16/AR15 Armorer, Glock Armorer
LaRue Armorer, Colt 1911 Armorer, Colt M16/AR15 Armorer, Glock Armorer
|
My earlier response about how I believe the OP was riding the charging handle, which regardless of how clean it is will cause it to not fully lock due to the gas rings. If anything, it demonstrates he has good, solid gas rings that are working and it is not a cleaning issue. With that said, you can easily clean the extension/star chamber area using a patch, and your pinky finger. Have you guys never gave any lady the shocker? You should be experts at using your pinky finger there and clean about 80-90% of it and the rest can use a bent q-tip that can go full 360 around the lugs and base/breech face. |
|
Originally Posted By dalle0001: With that said, you can easily clean the extension/star chamber area using a patch, and your pinky finger. Have you guys never gave any lady the shocker? You should be experts at using your pinky finger there and clean about 80-90% of it and the rest can use a bent q-tip that can go full 360 around the lugs and base/breech face. Are we about to have guys comparing pinky size now? |
"Technique isn't something that can be taught. It's something you find on your own." - Bunta Fujiwara
Tips for cleaning star chamber? (Page 1 of 2)
AR Sponsor
Join the Community
Your next conversation starts here.
Create your free account to join discussions, share your experience, save topics, and connect with the AR15.COM community.
- Join discussions
- Follow topics and replies
- Connect with fellow enthusiasts
Already a member? Sign in
Stay informed by subscribing to our Newsletter