Really, really dirty SBR, help

[tucansam]

So I have had my 12" Grendel ever since the Faxon group buy from a year (maybe two now?) ago.

I shoot it almost exclusively suppressed. I usually have to clean it after 40-50 rounds (factory ammo, for now) or else it becomes sluggish and tends to malfunction. A put an adjustable gas block on it, which helped a bit with the felt recoil (that was not the issue I was trying to fix), but did almost nothing for the soot and sludge the rifle generates. In fact, I neglected to clean it after one range session, and came back to clean it two weeks later, and the bolt had literally seized shut. I presume carbon had mixed with whatever lubricant was left over on the bolt, and the entire thing cemented shut. It took a friend and a rubber mallet to open the action.

Bottom line: I don't have any other rifles, SBRs or otherwise, that get this dirty.

I'm looking for additional solutions. I now have enough brass to start hand loading, so I can try cleaner powder, but that negates the $139 200 round Sportsman's ammo cans that I can use for cheap blasting. I can try a bolt carrier that vents gas, but last I checked those aren't cheap, and I'm not sure it would do anything for soot in the chamber, since gas is still reaching that point in quantity. I could close my gas block more, but then the rifle doesn't run. I could shoot it unsuppressed, but this is a hunting rifle that has had much success killing critters, and suppressed means I don't have to hike around with earpro on.

Any ideas would be great.

[snarkscarbine]

What buffer and buffer spring are you using?

[tucansam]

What buffer and buffer spring are you using?

Started with a standard carbine buffer and spring, then went to a 9mm buffer and standard spring, am now at a blue spring (forgot the brand, higher power spring) and standard buffer.

[A5BLASTER]

Sounds like you might need too dune down on the amount of lub you use after cleaning it. Might not fix the problem but might help it some.

You want a very thin layer, like rub by hand with a cloth patch soaked with lub, light pass, just enough so it isn't bone dry.

[Mad Charlie]

What buffer and buffer spring are you using?

What factory ammo are you using that is so dirty?

[Cereal Thriller]

over lubing condition is it made a paste with the fouling. Might try out a dry form of lube when running suppressed,

[Bigs28]

I have a 12" faxon with a tbac ultra 7 suppressor. It's dirty but i use a cryptic coating bcg in mystic bronze. Not a drop of lube in my rifle. Runs flawless

[ricsmall]

Find a recipe for red oil. Never mind, read linked article. I started making this stuff years ago and it works. Doesn’t gum up and carbon is easily removed.

https://www.rifleshootermag.com/editorial/ar-lube-advice-from-the-experts/83963

[Maddvaper]

Benchmark (1st) and 8208 (2nd) in my 12" has been my Cleanest burning powders by far , I use little to no lube and an H2 Buffer Standard carbine Spring.

[Klem]

Tucansam,

Your suppressor is the main cause of all that carbon/filth. Not much you can do about it except find a lube that won't carbonise too badly and use it sparingly. Make sure you spray that gun as soon as you get home because all that suppressor soot attracts moisture and will corrode. That goes for the suppressor itself. If you can't pull it apart then a spray of WD40 and stand it upright and let it flow out overnight so it's dry enough next time you use it. Just the downside of using a suppressor I am afraid.

[grayfox]

Klem is this cleaning for the can also true for the titanium ones, when they are over-size (like a 7.62 on the grendel...)?

[Popeye212]

Klem can the gas tube get clogged enough to constrict?

[Klem]

grayfox,
I used to have an outside tube titanium with alloy baffles and spacers. The build-up of soot ended up I could not unscrew the end cap easily, then the dreaded baffle strike was its premature demise.... I read titanium is like aluminium in that it's very reactive. This means it oxidises quickly but then gets a protective film.

With stainless/aluminium mix cans if you don't clean the can quickly enough after shooting you get that white powdery corrosion in areas of soot build-up. Definitely don't store the gun with a used suppressor on. Baffles closest to the muzzle absorb all the super-heated pressure so become pitted eventually. The WD40 straight after shooting is the manufacturers advice and while it doesn't take all the soot out it stops corrosion.

Wouldn't imagine there's much difference between a 6.5mm and 308 suppressor in amount of corrosion and carbon build-up. The clearance with a 6.5 is about 1mm (7.5mm baffles) and the 308 can will use 8.5mm baffles. An extra mm of clearance means it will be very similar.

Popeye,
Never experienced a clogged gas tube. I've seen pipe cleaners sold to clean gas tubes but never used one or seen one in action. I'm thinking the pressure tends to keep it free. A lot of the soot in an AR from using a suppressor comes from the chamber, not gas tube. It gets forced around the cases as they unlock. I've used a suppresed Adams Arms piston upper and the receiver and cases still ended up filthy.

[grayfox]

The Tbac ultra is 100" titanium and is 360* welded around the internal baffles. they have cleaning recommendations on their website in the tech notes area, using CLR or ultrasonic cleaning, if the can gains 2-3 oz of soot buildup.

[Klem]

The Tbac ultra is 100" titanium and is 360* welded around the internal baffles. they have cleaning recommendations on their website in the tech notes area, using CLR or ultrasonic cleaning, if the can gains 2-3 oz of soot buildup.

Sounds good...I cannot afford to wait until 2oz of soot has built up using stainless steel and alloy baffles but I guess with titanium the guys at TB think that's OK.

I use an ultrasonic cleaner, mainly for the cases. Unsupressed they just get tumbled but suppressed they are filthy. Into the ultrasonic bath for two lots of 20-mins. I use the juice of a lemon with some vinegar, salt, dishwashing liquid and water. The machine heats the water to 50C while the cases soak and then it runs. I deprime first to help drying. I use a hairdryer, even if it's summer to prevent staining. Into the oven on a tray at low temp for half an hour gets rid of any moisture the hairdryer doesn't.