A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

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Odd Job
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A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Odd Job » Sat Mar 26, 2016 7:24 pm

I bought an A-TEC CMM4 suppressor configured with 6 baffles. This is a rimfire suppressor currently on my SIG522. I've been weighing it and X-raying it after every 500 rounds, no cleaning.
Part 1 of my observations can be found here:

https://www.linkedin.com/pulse/lead-dep ... 1-bertolli

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by quiettime » Sat Mar 26, 2016 7:47 pm

Neat test. I guess this suppressor does not come apart?

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by whiterussian1974 » Sat Mar 26, 2016 8:42 pm

So 2-3g mass increase per 500rd mix for 1st 2000rds, then no added weight. Interesting.

IMAZING work !!! If you aren't getting paid by a publication, then you should show this work around as an example of your product.

Very professional layout, experiment, and presentation.
Love the imaging of lead scale buildup. It looks like screwapart modules. Can you clean it?
Would be interesting to see only copper-washed results.
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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by quiettime » Sat Mar 26, 2016 9:14 pm

whiterussian1974 wrote: Would be interesting to see only copper-washed results.
I thought the same.

I messaged CCI recently
quiettime wrote:Still waiting to find some of your Suppressor .22lr available. I love the idea of the 45 grain bullet but why not offer it in a plated bullet? Exposed lead produces a lot of lead spattering in a suppressor and a plated bullet would help. Please keep making more .22lr, it is still very hard to find any in stock here in Florida. I haven't bought any in two years!
and their response:

[quote="Justin M CCI "Expert""]Chris, the plaited bullet has the same Leading specification as a non-plaited bullet. The plating is a flash coating and doesn't help with cutting down leading, the bullet lube is what prevents leading. I'll leave the bullet selection up to the engineers.[/quote]

:roll:

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by whiterussian1974 » Sat Mar 26, 2016 10:03 pm

quiettime wrote:
whiterussian1974 wrote: Would be interesting to see only copper-washed results.
I thought the same. I messaged CCI recently
quiettime wrote:I love the idea of the 45 grain bullet but why not offer it in a plated bullet? Exposed lead produces a lot of lead spattering in a suppressor and a plated bullet would help. Please keep making more .22lr, it is still very hard to find any in stock here in Florida. I haven't bought any in two years!
and their response:
[quote="Justin M CCI "Expert""]Chris, the plaited bullet has the same Leading specification as a non-plaited bullet. The plating is a flash coating and doesn't help with cutting down leading, the bullet lube is what prevents leading. I'll leave the bullet selection up to the engineers.
:roll:[/quote] :roll: Well, that's 1 opinion. I wonder what others say?
We need Cpt, CMV, Gunny and others to weigh in.
(I've PM'd)
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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by whiterussian1974 » Sat Mar 26, 2016 10:35 pm

Brandon, Radiographer wrote:"I suspect that large flakes of lead may have been ejected from the suppressor at that session, but I cannot prove it because I have no means of catching the escaping residues where I shoot."
Spread a white sheet or something similar in front of muzzle. After done, you gather the sheet and collect any detritus. You can see the lead powder, and even weigh if scale has sufficient range. OTherwise just post: "pinch of lead" or "fine powder."
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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Odd Job » Sun Mar 27, 2016 4:56 am

Thanks gents for the kind words.
This suppressor will come apart with force, but the distributor says it is not meant to be taken apart. I have left it as is.

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Fulmen » Sun Mar 27, 2016 9:04 am

Odd Job wrote:the distributor says it is not meant to be taken apart.
That is odd, part of the benefit with these suppressors are the the ability to adjust the length by adding or removing modules. But they must be cleaned quite regularly or else they seize up. Most people just set them up to the desired length and let them be, but if the modules are loosened after each use they can be taken apart.
Have you called the manufacturer? I'm pretty sure they will say the same thing.

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by whiterussian1974 » Sun Mar 27, 2016 11:52 am

whiterussian1974 wrote:[quote="Justin M CCI "Expert""]Chris, the plaited bullet has the same Leading specification as a non-plaited bullet. The plating is a flash coating and doesn't help with cutting down leading, the bullet lube is what prevents leading. I'll leave the bullet selection up to the engineers.
:roll: Well, that's 1 opinion. I wonder what others say?
We need Cpt, CMV, Gunny and others to weigh in.
(I've PM'd)[/quote]Update:
gunny50 wrote:A goed friend of mine that worked at Federal in the R&D told me the same a while back, as copper coat is so thin its not really much help.

I'll check with him iff he would give me an update on this.

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by quiettime » Sun Mar 27, 2016 12:00 pm

When I dig bullets out of the ground there is still some copper on them. You would think it has to help

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by whiterussian1974 » Sun Mar 27, 2016 12:31 pm

quiettime wrote:When I dig bullets out of the ground there is still some copper on them. You would think it has to help
The land impressions probably expose the lead. Copper should help, but apparently not thick enough to PREVENT fouling.

Would Copper-plate fare better?

Good to know that wax lube helps. What about dry lube?
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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Capt. Link. » Sun Mar 27, 2016 1:42 pm

Leading of .22 caliber rimfires is well known.The lead is deposited through lead vapor and this is why ventilation is so very important when shooting indoors.The use of copper plated bullets may reduce this but the layer is very thin and probably vaporizes just like lead leaving a copper lead mixture.Shooting into large gummy bears and recovering bullets then examining the base under magnification should help confirm or deny this thought.

My own use with copper washed bullets has been for accuracy reasons.Every gun is unique in what it may shoot best.

The lubrication of .22 rimfires dose have a direct bearing on leading.If the lube runs out before the bullet exits the barrel a lead deposit will form on the last few inches of the bore degrading accuracy.If you have a rifle length barrel of over 18" you want to use a heavy waxed bullet like the RWS subsonics or other target grade with a heavy lube.The presence of this lead in the barrel may also contribute to leading of a suppressor as this lead would be subject to vaporization.This heavy lube should also helps prevent the vaporization of of the lead base in shorter barrels at the cost of the mess it makes in the can a catch 22.

To keep the mess down along with removal of much carbon with any suppressor. I find placing the suppressor in a lite hydraulic fluid or penetrating oil for a day or so then let drain works well.You could follow this with a wash in varsol to eliminate the oil residue.I don't remove this trace oils without any problems after over 30 years of using this procedure.

While not available to rimfire shooters a coating of nylon has proven to reduce it not eliminate the formation of lead gases.I would have to include gas checks and paper patching & wax paper wads with the possibility of powder coated projectiles as well.

I think with the ever growing trend of suppressor use the manufacturers may come up with more effective coatings .

Hope this helps

PS: WR I've been working on my eyesight ever since you changed your avatar!

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Odd Job » Sat Apr 09, 2016 11:10 am

That is odd, part of the benefit with these suppressors are the the ability to adjust the length by adding or removing modules. But they must be cleaned quite regularly or else they seize up. Most people just set them up to the desired length and let them be, but if the modules are loosened after each use they can be taken apart.
Have you called the manufacturer? I'm pretty sure they will say the same thing.
I contacted A-TEC and their advice is that although the suppressor can be taken apart, they had so many problems with customers calling to say they can't put them back together, that they now recommend you don't take it apart.

Currently the suppressor is up to 3500 rounds and it now weighs 144g.

I can't explain the weight fluctuation, I thought it would hover at the 140g mark. More shooting needed.

By the way I bought an ASE Utra can (my 3rd one) and I will be doing the same experiment with that one, so stay tuned.

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by David Hineline » Mon Apr 18, 2016 8:47 pm

If/when you actually take this apart. I suspect you will find that lead is not most of the problem, carbon hard almost glass hard like material from powder burn will be the most of the build up filling every nook and cranny locking things up solid.

Also not as dense as the base material of the silencer so not showing up in your image captures.
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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Odd Job » Tue Apr 19, 2016 2:19 pm

I suspect you will find that lead is not most of the problem, carbon hard almost glass hard like material from powder burn will be the most of the build up filling every nook and cranny locking things up solid.
I doubt that, since I don't find deposits like that in my other suppressors which I do take apart (and which have many rounds through them also, using the same ammo)

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Odd Job » Sat Apr 30, 2016 6:14 am

Here's the update after 4000 rounds:

Image

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Odd Job » Thu Jun 16, 2016 4:01 pm

Now at 5000 rounds:

Image

You can see when comparing the end baffle zone at 4500 rounds to 4000, at least three large pieces of lead were ejected from the suppressor. This helps explain how the weight of the suppressor can fluctuate.
Note that the overall trend is still upward: the suppressor now weighs 20g more than it did when new!

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by whiterussian1974 » Sat Jun 18, 2016 1:09 am

Something else which I notice, the endcaps are more radio-opaque @0rds than after use. This is an artifact of "Digital" radiography. The contrast auto-changes to give greater clarity to the lead deposits. Otherwise, they would be far "darker" than we would be able to see the details in the leaded baffle sections. :)

The 4k to 4.5k rd images appear to show those "3 large lead pieces" to have 'transferred' to the next sequential sections rather than "ejected." Notice how the "furriness" seems to move to the later stages. From sections #0-2 into sections #3-5.

It's the 2.5k image that's the anomaly. I wish that an expert Radiographer would explain what this image shows.

Maybe someone knows a Nurse that can ask an X-ray tech?
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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Odd Job » Sat Jun 18, 2016 6:15 am

Something else which I notice, the endcaps are more radio-opaque @0rds than after use. This is an artifact of "Digital" radiography. The contrast auto-changes to give greater clarity to the lead deposits. Otherwise, they would be far "darker" than we would be able to see the details in the leaded baffle sections. :)
It's a mixture of exposure differences on the X-ray unit and manipulations in Photoshop. As the suppressor has picked up more lead, I have had to increase the kV. Subsequent tests with other suppressors will be done with a range of exposures and an aluminium step wedge for reference.
The 4k to 4.5k rd images appear to show those "3 large lead pieces" to have 'transferred' to the next sequential sections rather than "ejected." Notice how the "furriness" seems to move to the later stages. From sections #0-2 into sections #3-5.
Those aren't the areas I am referring to. I am talking about the end zone after the last baffle, you can see two lucent areas with clear borders and an area that was previously packed with lead and which now isn't, from 4000 to 4500 rounds.
There is nowhere else for that lead to go, other than out of the suppressor.
It's the 2.5k image that's the anomaly. I wish that an expert Radiographer would explain what this image shows.
Maybe someone knows a Nurse that can ask an X-ray tech?
I am a radiographer, so we don't need to "phone a friend" :o
All you can say, when looking at 2500 compared to 2000, is that there are several areas where there was lead build-up at 2000 which are less dense at 2500. From 4000 to 4500 a lot of material was lost from the end baffle and the end space, but also a lot of new material collected on the underside of baffle number 4 which wasn't present at 4000 rounds.

I'll be putting a follow-up post on LinkedIn explaining it better...

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Odd Job » Sat Jun 18, 2016 7:37 am

The other thing to note is that the native format of the images is DICOM. A radiologist or a radiographer evaluating these images would be doing so with the appropriate DICOM viewer, where you can better manipulate the images in terms of the window width and level. To simplify the explanation, the viewer has the facility to alter the number of greys used to display the image, and the density of interest (which density sits in the middle of those greys).

The images I post online are jpegs derived from one of many possible manipulations of the image in the DICOM viewer. So they are a lossy, static representation of what I have available on my PC.

Nonetheless they are good enough to demonstrate where the lead is accumulating from one image to the next.

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by whiterussian1974 » Mon Jun 20, 2016 2:58 pm

Odd Job: You make all great points. Thank you not only for your time and effort in capturing the radio-graphs, but also for lending us your expertise in evaluating and interpreting them for us. :)
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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by RPM509 » Tue Jun 21, 2016 8:05 am

Can the atmospheric conditions before, and while shooting contribute to the uneven buildup throughout the total cycle?
Maybe on higher or lower humidity days more or less lead and carbon fouling is adhering to the suppressor? Might
explain the odd accumulation.

Very interesting study regardless.
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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by whiterussian1974 » Wed Jun 22, 2016 1:15 am

RPM509 wrote:Can the atmospheric conditions before, and while shooting contribute
The only anomaly is the 2500rd image. The others show aprox ~3g increase per 500rds. (+/- .5g/500rds)
Humidity and temp shouldn't have this effect. Lead doesn't have this property.

Oddjob's explaination of fractures developing within the lead weld mass and blowing loose during the 2k-3k cycle seems the best.

We'd need more info on storage conditions, rough handling during transit, use, etc before we could make any guesses founded in science. But I think that he is correct about the findings, results, conclusions surrounding lead buildup and retention.
----
Maybe it's time to UltraSonic clean the lead loose and start a new Trial. Coating the internal surfaces with Li soap or DOT3 brake fluid to see if the combination causes the lead spatter to slide off of the surfaces and cool/harden so that it shakes loose as dust, instead of the molten lead clinging to baffles.
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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by Tony M. » Wed Jun 22, 2016 10:54 am

whiterussian1974 wrote: Maybe it's time to UltraSonic clean the lead loose and start a new Trial. Coating the internal surfaces with Li soap or DOT3 brake fluid to see if the combination causes the lead spatter to slide off of the surfaces and cool/harden so that it shakes loose as dust, instead of the molten lead clinging to baffles.
If you coat it with brake fluid, please use DOT5, NOT DOT3!

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Re: A-TEC CMM4(6) Rimfire Suppressor Lead Deposition

Post by whiterussian1974 » Thu Jun 23, 2016 12:13 pm

Tony M. wrote:If you coat it with brake fluid, please use DOT5, NOT DOT3!
https://en.wikipedia.org/wiki/DOT_3 wrote: DOT 3, like DOT 4 and DOT 5.1, is a polyethylene glycol-based fluid (contrasted with DOT 5, which is silicone-based). Fluids such as DOT 3 are hygroscopic and will absorb water from the atmosphere.
My mistake. :oops:
Darn sleep deprivation. :( (Posted: Wed Jun 22, 2016 12:15 am)
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