I thought you guys would find this interesting since people like to think that rifle silencers "self clean" themselves and don't get filled with copper, lead, carbon, etc like handgun and rimfire silencers do.

This first cutaway pictured below is a prototype CGS Group Hyperion 762 that took the abuse of 12,800 rounds of Nexus 260 Remington through an 18” semi auto host (wood background). The Hyperion is 100% billet Grade 5 titanium, and it was also obviously never cleaned during the stress test. Note how the particle erosion of the blast baffle and the subsequent baffles is virtually nonexistent. You can also clearly see where the different materials have built up with copper in the first section and carbon in the forward section. It's not lead up front since all the rounds fired through the silencer had a completely sealed copper base.

Whether or not you need to clean a rifle silencer is dependent on the cartridge you’re shooting, firing schedule, barrel length, etc. The best way to see if you need to clean a rifle silencer is to just weigh it every couple thousand rounds. Ase Utra in Finland references an average of 1 gram of buildup per 100rds depending on the cartridge, quoted at the bottom of this post. Tuukka also goes over the effects fouling can have on sound reduction, flash, and accuracy. Depending on the can, clean it out with a solvent or throw it in an ultrasonic cleaner, or when provided do what the manufacturer says.

After I'd posted our Hyperion silencer cutaway on Instagram, Wedgetail Industries in Australia was nice enough to post a cutaway of their rifle silencer with nearly the same round count. The Wedgetail Ninox silencers shown below are an unspecified high temperature alloy (listed as titanium on their website though) and are more traditional in design, using ported cone baffles. It's very useful for demonstrating build up in traditional silencers. The following four pictures on a white background are of their Ninox rifle silencers with 12,000rds of 308 fired through them.



Wedgetail Industries Ninox silencers at 12,000rds of 308:






And I'll also include this brief write up by Tuukka Jokinen of Ase Utra in Finland on silencer cleaning:

What's the best way to clean a sealed can?

I wish I had access to an ultrasonic cleaner with enough oomph to do a good job.

If it's completely titanium - I recall Thunderbeast has some instructions floating around on using CLR as a solvent to clean them out.   It might take a little while, but that will eat every last bit of crud out down to the bare metal.   Might also redeposit some of the copper on random things.

Be warned, it will eat steel when it starts running out crud to dissolve.

I think I'm going to try Carbon-Off on some stuff in the future and see how it goes.

I've seen posts where SureFire recommended CLR as well. That's my plan once I've got 3-4K through my SF cans.

I used CLR on a muzzle brake and it worked well.
What would be the best way to apply it to a can, submerged the whole thing?
I would think that'd be tough on the finish?
Maybe plug one end, fill it up, and plug the other end?

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Wow!  That worked great, do you have to neutralize it with something to get it to stop eating the carbon?

I don't think it's that strong but it may be.
I may have put a light coat of oil on it after cleaning but don't remember.
Neutralized it with more gun powder

Haha, sounds good.

For a can, I'd plug it, fill with CLR, leave it standing for however long you're comfortable with (IIRC, the SureFire rep said overnight, but don't take my word on that), empty it out and wash with water, then blow it out with compressed air.

Does the resulting contaminated CLR require any special disposal?

You'd think that manufacturers in the US would offer cleaning services for a small fee.

Seems like they'd get MORE business in the long run with how heavily customer service-centric the US market is.

Carbon and CLR? Maybe.
I put the lid on it for use later.

I am seriously considering a sealed pistol/subgun can like the wolfman but this is one of my concerns. They say you risk damaging the finish if you use ultrasonic

Yep...that is why I stay away from sealed cans as much as possible.  I was considering the Omega9K, Wolfman but don't like the idea of a welded subgun can.  Maybe consider the Rugged Obsidian since you can take it apart.
I've always been a huge fan of the old Gemtech MK9K which I've put many thousands of rounds in full auto on mine.  I just had Curtis Tactical make me a shorter version that is completely serviceable with 17-4 SS baffles.  I just remove the baffles and chuck in the ultrasonic.  Should be able to do the same with the Rugged Obsidian.

I assume a rotary tumbler with stainless pins would work too? Have one for cleaning reloading brass. Do you use any kind of soap? I worry about CLR damaging the rubber inside the tumbler.

Is it recommended to clean the tube too?
Sorry just got my first suppressor. Haven't shot it enough to need to clean but someday...

Should have specified; my suppressor is not sealed and I would toss the baffles and spacer l spacers in. They're all titanium. The tube is also titanium but is painted so I'll likely deal with that separately.

Excellent post. Thanks.

(off to buy some CLR)

Empirical data, always welcome. Interesting appearance on the cutaways, as well!

How long was it in there for?

I think it was 2-3 hours.

The soak removed 95% of the build up. Wiped it off after. Scrapped a small amount off with a knife.

I think I would be worried about chunks of stuff loosening after cleaning, but not coming out until fired.  Possibly causing a strike.

I've wondered that too. If you soak a heavily fouled can in whatever solvent, how can you be sure that there aren't any loosened up chunks in there that could break loose during your next range visit and cause a baffle strike?

Because those chunks wouldn't be there in the first place if the user was taking care of their rifle silencer like they're supposed to.

If it's heavily fouled like the silencers in the pictures I've posted, the best bet is an ultrasonic bath in combination with a solvent wash blown out and repeated until the silencer weight is near equal to its original stock weight. I can't think of a time where a "chunk" of debris randomly happened to fall into a bullets path and caused a baffle strike after being cleaned. There are already heavily fouled silencers constantly in use that have been cleaned in ultrasonic baths at really high round counts, and I've never heard of that being an issue. Then there's the people that already use CLR/solvents to clean their silencers. That type of thing hasn't been a reported or verified issue that I've ever heard of, but maybe @mageever or @Atlmike have heard of that happening and would have input from their high round count silencer tests? The Wedgetail Industries silencer uses ported cone baffles which are similar to the AAC M42000 which has been in service for around a decade. I'm sure some of those hit really high round counts as well and were cleaned. I wouldn't worry about it.

OSS has a good video on one method for "flow through" type silencers: Here

That's something people will also be able to do on future Hyperion models.

Is this the Calcium, Lime, Rust Remover CLR or something else?

This stuff. Works great on the bathroom too.

After seeing those cutaways, as of about 4 hrs ago my oldest, most heavily used M42000 has been soaking in CLR. I’ll give it a day to see what crud I can wash out... The blast chamber at least was pretty fouled-up with stuff I’d have to chisel out otherwise.

To remove lead fouling, on a stainless steel suppressor, there's also "the dip" which is highly effective at dissolving all lead deposits.

But it creates lead acetate which is very, very dangerously poisonous.    However, it can be neutralized with ordinary salt.

The dip will attack aluminum.   It's best used ONLY on stainless cans.

The dip is made from a combination of vinegar and hydrogen peroxide, which creates lead acetate when brought into contact with lead.

Afterwards would you just dump a bunch of salt in and be okay to throw it away or does it still go to a hazardous waste center?

If the suppresor has aluminum, inconel, stainless and titanium what's the best solution for an ultra sonic bath to removing fouling without causing damage?

I'd be very careful with aluminum in an ultrasonic.  Here is a an old thread: https://www.ar15.com/forums/Armory/Aluminum-parts-and-ultrasonic-cleaning/20-488875/

What was the weight increase after that round count?

Best Regards!

Tuukka

Tag for later

I believe the salt just stops it from eating lead and other metals. You still have lead acetate. Still poisonous.

I'm no chemist, but my rudimentary understanding is that the salt will take the lead out of solution. Someone will be along shortly to correct me.

I'm assuming an Inconel can like the Sig SRD762 would be fine in "the Dip"? I'll probably try soaking it in CLR first but thought I'd ask before I FUBAR'd anything.

Just a reminder for those who might have glossed over it; CLR will eat little pits in steel if you leave it in long enough.

I wouldn't go for more than an hour without checking it; you probably want to take it out when it stops fizzing on the carbon.

Not sure off the top of my head. I'll have to check and report back on that.

That's the wrong take away. The CGS Hyperion posted above isn't a coaxial flow through design and it's not as complex as it seems. If it was a flow through type silencer it'd have even less fouling than it does in the first picture because the carbon in the forward section would be nearly nonexistent. And as I said above, future Hyperion models will have that capability and it makes cleaning a bit easier.

The amount of fouling in the baffles of the Hyperion compared to the traditional silencer design is obviously much less, and the copper and lead are almost completely separated into different areas. The CGS Hyperion is the top picture of three pictures in one with the wood background showing the close up of the copper section and the carbon section under the full length cutaway. It was fired with 12,800rds of Nexus 260 Remington on an 18" semi auto host which is abnormally short for that cartridge. The other four pictures with white backgrounds are of the Wedgetail Ninox silencers. I'm not sure what ammo type the Wedgetail silencer was tested with, I just read 12,000rds of Australian made 308 and I don't know the host or barrel length. Maybe they'll pop in and say.

At the worst possible conditions with firing equally high round counts of exposed lead base ammo, the worst thing that could happen with the Hyperion being heavily fouled is that it would start to perform like a normal silencer for sound and possibly flash reduction. If you're just looking at the side view it may look like it's just completely caked with carbon up front, but it isn't. Only ~90 degrees of the bottom portion has that level of carbon fouling and the majority of the fouling is kept in that non-critical area around the forward core instead of completely filling the baffles as it does in a traditional silencer. Traditional silencer designs would lead to premature loss of the silencers sound and flash reduction when compared to the Hyperion design. Or a better way to say it is that the Hyperion design would maintain its sound and flash reduction for a much longer period of time without cleaning compared to traditional designs. Only the last two baffles in the Hyperion have a similar level of carbon fouling as the traditional silencer. The other benefit of the Hyperion design its that there is almost zero particle erosion of the blast baffle. Looking at it close up there isn't even any pitting of the metal. And looking at that area, the section where the cutaway was taken is where the thickest portion of the build up is located. Looking down the baffles the build up isn't nearly as much as it seems just looking at it from the side. Only the bottom ~45 degrees is filled with copper. The rest of the baffle is clear with exception of the blast baffle. If the section was taken at a different angle you'd only see copper build up at the blast baffle and a bit of carbon around the forward core and some carbon in the last two baffles. But this looks cooler.

None of the silencers I posted pictures of are flow through silencers. You're the guy that said "The post is making complex internal geometries and coaxial flow through designs look worse than other designs for fouling" but none of the pictures in my post are of that type of silencer, which makes it seem like you're talking about the Hyperion which is what many would determine to be the seemingly more complex silencer of the bunch pictured here since it can also be made into a flow through silencer. Maybe OSS silencers have fouling in those exterior areas to a point that it matters, but I don't know that for sure and you don't know that for sure either. So you're just speculating on what the inside of a flow through silencer *might* look like based on the amount of fouling in the pictures I posted, even though in flow through designs the fouling has an exit besides the bore which would indicate that to a point that flow through silencers have the capability to run a bit cleaner than a traditional silencer depending on the design. Maybe not on OSS, but we don't know one way or that other so it's pointless to speculate. So you're not trying to disparage our product directly. I get that, glad we figured that out.

Until someone does a comparable high round count test on an OSS Helix and cuts it in half, the only people that will know if layering with spirals in flow through silencers gets fouled to a point that matters is OSS and the people doing the testing. Fouling can clearly stick, but in the case of current production CGS rifle silencers, not the one in the cutaway, they're internally coated to help prevent copper/lead/carbon from sticking as easily as it would on untreated metal.

And now you're trying to accuse me of cherry picking ammo "a little" in a post that wasn't meant to be a comparison, or even the topic of the post, which is a weird thing to do considering all the times I've defended Griffin and your products online when I didn't have to. Like I just did a bit yesterday. The comparison between the CGS Hyperion and the Wedgetail Ninox is not at all "cherry picked". The Hyperion was tested with that ammo for a very specific reason and that reason wasn't because it might look cleaner in comparison when another company eventually decides to post their silencer cutaway at a near equally high round count that might be using exposed lead based bullets. Do you know where else I can find a picture of another rifle silencer cutaway with 12,000rds fired through it? Because I sure don't.

The Wedgetail silencer wasn't even posted online until after ours was already posted. Wedgetail saw my cutaway and decided to post theirs as well on their Instagram page for everyone to see. I posted this OP because it was a cool comparison between two different types of designs at very similar round counts and it completely dispels the BS myth that people like to propagate about not having to clean rifle silencers. I included the Wedgetail Ninox cutaways because I didn't want people thinking that the CGS Hyperion, being a nontraditional design, gets any more fouled than a traditional silencer does. Without having a more traditional design to compare it to, that'd be more difficult to get people to believe. It's already hard enough getting people to believe the sound reduction capability of it.

It's pretty pointless to complain about alleged cherry picking. It's not like I had anything else to choose from. Wedgetail can't even sell on the US civilian market. And if you really want to compare stuff, even if the Hyperion was fired using exposed lead based bullets it'll still maintain sound/flash reduction longer than a traditional baffled silencer despite the fouling at the same round count, but that's not the point of the OP. If we actually wanted to be disingenuous and show it as super clean it could've just been cut at a slightly different angle and all of that fouling would be nearly gone. But we didn't, because that'd be dishonest and we have no reason to lie or make stuff up. And it'd look boring. Maybe we'll take the time to do 12,000rds of more common 308 on a production version in the future and then do an actual comparison against someone else's silencer first by weighing them before and after and comparing the added weight, and measuring sound/flash reduction before and after, then by cutting them in half and posting the cutaways.

Unless Wedgetail comes in here and says that their silencers were tested with exposed base bullets, then you have no knowledge as to whether or not their silencer was fired with exposed lead ammo anyway. And it really wouldn't matter because that isn't what the original post is about. It's to dispel a common myth about not needing to clean rifle silencers.

@RLunyATL

Correct.  Lead acetate is highly soluble in water.  It or lead nitrate are both soluble in water but many lead salts are not.  Lead sulfide is probably the least soluble but it's difficult to handle soluble sulfides like sodium or potassium sulfide.  Lead chloride is not very soluble and is fine.  However, a good alternative is sodium or potassium sulfate since it forms lead sulfate which is less soluble than lead chloride and not much more soluble than lead sulfide.  I would form the sulfate and put it out with regular trash given the small amounts people would be dealing with.

You can see that most of the buildup in the cans is lead from the exposed lead base of FMJ bullets.

Just use a couple FULL POWER rounds and it'll blast that shit out.

Lol.

I was gonna say lol too

That build up is from 'FULL POWER' rounds

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If you own a rimfire or a pistol can, this writeup is calling your name. As for you higher caliber suppressor owners (e.g., 5.56mm, 7.62mm, and large bore), you know from our last post that most rifle units are self-cleaning, but feel free to read along anyway!

Rifle Silencers As a general rule, higher caliber silencers don’t need to be cleaned/maintained. Considering most are sealed units, the ability to break them down and service this category simply doesn’t exist.  There are a few exceptions to this rule. Most notably, the Griffin Optimus and Alpha suppressors.  To that point, because the high velocity ammo used blows most buildup away, rifle cans basically clean themselves. It’s a phenomenon known as “carbon in, carbon out.” A typical centerfire rifle cartridge has enough pressure moving behind the projectile that the silencer will create carbon buildup, but it’ll also have enough “oomph” to push the old carbon out. (In other words, science.)

Rifle Suppressors They don’t really need to be cleaned at all. The overwhelming majority of rifle suppressors can’t even be disassembled. Advanced Armament Corp. (AAC) states that their sealed rifle suppressors can handle up to 30,000 rounds without any decrease in sound reduction.

As a manufacturer I recommend to my customers that they clean by firing. I've yet to see any issues from not cleaning them but I've had a few issues from guys that did clean.   Good luck Frank

Centerfire Rifle Silencers  Don’t clean centerfire rifle silencers. Article complete.  Okay, centerfire rifle silencers require a little maintenance. Keeping the mounting surfaces clean, whether that’s some kind of muzzle device or a thread on silencer, is the main objective. Certain types of silencer mounts are prone to failure if not maintained (thankfully there are fixes for the worst offenders). Nobody likes to launch a can downrange but it definitely happens. Most centerfire rifle silencers are not designed to be taken apart, and doing so will mess them up and void the warranty and probably lead to someone in customer service to committing suicide or homicide. A few general rules do apply to centerfire cans: don’t use cleaning patches, but bore snakes are fine. If you soak them in anything (you really shouldn’t need to) let them completely dry before firing, and make sure they align properly with the barrel before firing.

Centerfire rifle cans? Don't worry bout it. Just do a mag dump of full power ammo. That will break apart/dislodge/blow out any carbon buildup.

I turn my sarcasm meter off in the tech forums, so you need to be blatant about it.

So, how do you clean this stuff out then without ruining a can?

Say a Specwar 556 with heavy use?  What is best?

I can say from experience that an ultrasonic cleaner with Lyman Turbo Sonic will take the finish off a AAC Tirant 9

The one thing that has always bugged me about centerfire rifle cans; they are all sealed.  At least the ones I've been interested in anyway.

At least all pistol cans worth owning are user serviceable these days.  None of the methods of cleaning a sealed can mentioned in this thread seem appealing to me.