22LR Form 1 Suppressor w/ AAC-style K-Baffles

Yes, it can be legal to make a silencer. For everything Form-1, from silencer designs that are easily made, to filing forms with the BATF, to 3D modeling. Remember, you must have an approved BATF Form-1 to make a silencer. All NFA laws apply.

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Matt in TN
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22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Matt in TN » Thu Nov 30, 2017 10:10 pm

After a 13 month wait for approval from the almighty FedGov and about 40 hours of machine time, I've finally finished my first made-from-scratch suppressor. Final specs: 5.4" long and exactly 9.0 oz.

316SS seamless tubing and 416SS internals, all turned on a 1955 Southbend 9A lathe and who-knows-how-old Russnok vertical milling head on a horizontal mill base. No DRO or CNC, thank you very much - all old school hand-crank and dial reading!

Finished product, blasted and Gun Koted:
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Finished baffles (6 of the 9) and end caps:
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First operation: cutting the cones from 4416SS bar stock
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Second operation: turning the bottom trough
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Turning operations complete;
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Plunge cutting bottom mouse hole with a 1/4" ball end mill:
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Cutting the top mouse hole with a 1/4" ball end mill:
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Making the kidney-shaped cuts with an 1/8" ball end mill:
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Using a rotary table to take the kidney-shaped cuts through a 45° arc:
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Cutting the alignment slots:
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Cutting the alignment tabs:
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Cutting the wrench flats on the end caps:
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fishman
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by fishman » Thu Nov 30, 2017 10:34 pm

Very nice work. How's it sound?
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Matt in TN
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Matt in TN » Thu Nov 30, 2017 11:18 pm

fishman wrote:Very nice work. How's it sound?
Pretty good. I'm waiting on some "quiet" ammo to really give it a good test. Hopefully it'll be here this weekend.

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Enfield577 » Fri Dec 01, 2017 12:10 am

Good work, well done
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by T-Rex » Fri Dec 01, 2017 9:24 am

Congratulations. Loving the old machines!
For future reference, you should be able to go much thinner with the SS. The 22lr won't put up much of a fight.
Are all of your baffles identical or did you modify the blast baffle?
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Matt in TN
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Matt in TN » Fri Dec 01, 2017 9:52 am

T-Rex wrote:Congratulations. Loving the old machines!
For future reference, you should be able to go much thinner with the SS. The 22lr won't put up much of a fight.
Are all of your baffles identical or did you modify the blast baffle?
Thanks! 0.050" walls felt scary thin already! All baffles are identical. I thought about adding dater (?) holes to the blast baffle, but was worried it might increase first round pop. As-is there is no discernable difference between the first and consecutive shots.

What kind of mods would you suggest?

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T-Rex
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by T-Rex » Fri Dec 01, 2017 6:45 pm

Nah. I'll thin Al down to .05" in some areas. No failures yet. My primary baffles, in anything not rifle, is thin SS (.03-.035 area)

Yes, a dater hole is an additional feature which can be added to the face of the blast baffle. Often times, the blast baffle will not get a scoop or vent cut and only receive the dater hole. Some say this is more beneficial for pistol calibers, but can be found in a good number of 22 designs. Unfortunately, the Form 1 doesn't give you the ability to experiment so you're at the mercy of the final product.

Not a big deal, but Mouse holes are outdated features. The cut in the baffle face, between the kidney bean cuts, is a scoop or clip. The cut which allows the gas to occupy the coaxial space is a vent cut.

What is your POI shift look like? K's can often negatively affect flight path.
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by ECCO Machine » Fri Dec 01, 2017 8:08 pm

Looks good! That's a lot of sweat equity :shock:

As noted above, way over-built for .22 long rifle, should be plenty strong for magnum and even .22 Hornet or 5.7x28. On my .22 LR only monocore cans, I use 7075-T651, and the baffles are just .040" thick. Even those will handle magnum out of a rifle, though the pressure and heat of the 4.5" barreled PMR-30 proved a bit much in rapid fire.
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Matt in TN
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Matt in TN » Sun Dec 03, 2017 4:56 pm

T-Rex wrote: Yes, a dater hole is an additional feature which can be added to the face of the blast baffle. Often times, the blast baffle will not get a scoop or vent cut and only receive the dater hole. Some say this is more beneficial for pistol calibers, but can be found in a good number of 22 designs. Unfortunately, the Form 1 doesn't give you the ability to experiment so you're at the mercy of the final product.
I understand I can't experiment - I'm just trying to learn and understand: what is the point of the dater holes? In my head all they do is allow expansion from in front of the blast baffle to the 2nd chamber, which would help lower the pressure in the blast baffle. But since this is a low pressure cartridge I didn't think it was needed. Does it also reduce noise levels or change the tone?
T-Rex wrote: Not a big deal, but Mouse holes are outdated features. The cut in the baffle face, between the kidney bean cuts, is a scoop or clip. The cut which allows the gas to occupy the coaxial space is a vent cut.
I've always been "outdated" - you should see my wardrobe! What is the newer/better design? A more complex monocore? I don't think I can do that very well with manual machines. I think I did the scoop for the baffle hole and the vent for the other side (it's easier to see in the drawings behind the baffles). I pretty much downloaded the AAC patent, tried to understand it, and apply my own dimensions to it.
T-Rex wrote: What is your POI shift look like? K's can often negatively affect flight path.
I had to get out and test that today just because you asked! This is only at 10yds and I was shooting freehand, so it's not a GREAT test of POI shift. There seems to be a slight shift down and left. And either it's more accurate suppressed, or it allows me to shoot more accurately more easily suppressed. Either way, I'm happy. Still waiting on the "quiet" ammo -

Image

And just because it was funny (when I showed my wife my holstered suppressed pistol):

Wife: That looks ridiculous! You look like Starbuck -
Me: I think you mean "awesome."
Wife: No, I mean ridiculous.

Then I realized that Starbuck was awesome, and every woman in the Galaxy totally wanted him.

Image

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by gunny50 » Mon Dec 04, 2017 6:02 am

Matt,

That is an awesome looking build, would you post the DWG?

Gunny

Matt in TN
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Matt in TN » Mon Dec 04, 2017 8:56 am

gunny50 wrote:Matt,

That is an awesome looking build, would you post the DWG?

Gunny
I wouldn't mind a bit to, but since this is someone else's patented baffle I'm hesitant to post it on an open forum. I'm sure this has come up before here though - what are the forum rules/norms on that?

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by fishman » Mon Dec 04, 2017 12:09 pm

Matt in TN wrote:
gunny50 wrote:Matt,

That is an awesome looking build, would you post the DWG?

Gunny
I wouldn't mind a bit to, but since this is someone else's patented baffle I'm hesitant to post it on an open forum. I'm sure this has come up before here though - what are the forum rules/norms on that?
Reverse engineering something then posting a drawing isn't illegal. If you aren't using the drawing for monetary gain you're fine. The (undimensioned) drawings are included with the patent and are public record anyway.

https://patentimages.storage.googleapis ... D00005.png
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by T-Rex » Mon Dec 04, 2017 1:17 pm

fishman wrote: If you aren't using the drawing for monetary gain you're fine.
Monetary gain is not a prerequisite for Patent infringement. Also, posting a dimensioned drawing, of a patented item, could be construed as specific intent; which is a civil violation. Pretty much, you knew the invention was patented and, by supplying the drawings, knew someone else's intention to infringe upon it. IMHO, since Gunny asked for it, the item's US Patent doesn't protect it from international infringement :wink:

Aside from all that nonsense, take note of a few things:
Whenever we patent, publish, trade, and/or supply clients w/ proposal drawings, nothing is to scale or accurately depicted. Sure, the overall package looks like what will be promised, but simple skewing of minute, yet critical, details protects our design(s). Photos are much more reliable, because they're usually of a final production piece, which would be accurate.

Your K-baffles obviously work, but there's no telling how close to AAC's actual design you got, merely by scaling a patent drawing.

If it's quiet and you can hold tight groups, you've got a success :D
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Matt in TN » Mon Dec 04, 2017 4:10 pm

T-Rex wrote:
Your K-baffles obviously work, but there's no telling how close to AAC's actual design you got, merely by scaling a patent drawing.
Yep. I really didn't scale the drawings - more read the patent and tried to undertsand what they were doing and why. Then applied my own dimensions that I thought might accomplish those goals. And to be honest, most of my dimensions were chosen as much for ease of manufacture (eg: I have a 1/4" and 1/8" ball end mill) as anything, and they looked close enough for what I was trying to do.

Sorry Gunny - but with all that said I think I'll hold off on posting the dimensioned drawings. Not saying you'd do it, but knowing my luck some schmuck would either use them to blow himself up, blame me for his crappy suppressor, or go into production and steal money from AAC wih their own design.

And "success" for me was defined by being a fun project that forced me to take my machining skills and understanding of suppressors to the next level. I'm sure the suppressor could be improved, but almighty FedGov says "nyet". So it's plenty good enough as-is.

Now I get to decide whether .308 or .45 is next on my plate...

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Paco664 » Tue Dec 05, 2017 6:35 pm

thats awesome... and thanks for the photos... i enjoyed this...

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by delta9mda » Mon Jan 08, 2018 5:00 pm

ill let others bicker about the plans, masterful work man.
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by a_canadian » Mon Jan 08, 2018 10:15 pm

Very tidy work Matt. The smooth finish should make for easy cleaning, and your extra thickness in stainless will probably make it a viable suppressor for hundreds of thousands of rounds fired so long as you keep it reasonably clean. I'd have to concur with it being significantly over-built, but hey, with the small dimensions and only 9oz weight that's not really a problem. With a 9 baffle count I'm guessing it's going to be very pleasant sounding with something like CCI SV, and practically finger-snap quiet with CCI Quiets, though for the latter you'd want to swap springs for something very weak to have any chance of semi-auto function. Just guessing - I've never tried the weakest CCI rounds in a Ruger, perhaps they'll cycle with a standard spring. Anyway, admirable work.

Have you tried the two basic indexing orders and compared informally whether one is better than the other for suppression? What I mean is testing with all ports facing the same way, then testing again with port direction alternating in a zig-zag pattern. I've not found any significant difference, but do find that for PCP airguns or rimfire there's more significant POI shift with all ports going the same way.

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Rrdstarr » Wed Jan 10, 2018 7:06 pm

Give some Gemtech ammo a try. I found it to be the best out of my MK III 22/45.
OVER engineered! You could use that on .22 centerfire.

Well done!
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by delta9mda » Wed Jan 10, 2018 9:57 pm

Awesome job and don't worry about the nannys crying over a few ounces. And those are x baffkes to be more precise.
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by alordnapa » Wed Jan 17, 2018 11:45 am

Mitch Rapp called, and he wants his pistol back!

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Matt in TN » Thu Feb 08, 2018 10:39 pm

Thanks guys. I have not tried all the ports in the same direction, but I did pickup a little breakdown 10/22 to play with. It works great on both, of course!

The CCI Quiets are perfect sounding in the pistol but don't cycle it. The CCI SV is OK in the pistol, but it really shines in the 10/22. Tons of fun!

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by BinaryAndy » Thu Feb 08, 2018 11:06 pm

That holster. I need that holster.
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Matt in TN
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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by Matt in TN » Sat Feb 10, 2018 1:24 pm

BinaryAndy wrote:That holster. I need that holster.
Here's a tip - everyone on the internet said "You want the high rise version" of that holster, so I bought it. I know this will blow your mind, but everyone on the internet is an idiot. I really wish I bought the low rise.

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by fishman » Sat Feb 10, 2018 2:58 pm

Matt in TN wrote:everyone on the internet is an idiot.
300 blackout form 1: http://www.silencertalk.com/forum/viewtopic.php?f=10&t=137293

5.56 form 1:
http://www.silencertalk.com/forum/viewtopic.php?f=10&t=141800&p=955647#p955647

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Re: 22LR Form 1 Suppressor w/ AAC-style K-Baffles

Post by alordnapa » Sat Feb 10, 2018 10:09 pm

Matt in TN wrote:Thanks guys. I have not tried all the ports in the same direction, but I did pickup a little breakdown 10/22 to play with. It works great on both, of course!

The CCI Quiets are perfect sounding in the pistol but don't cycle it. The CCI SV is OK in the pistol, but it really shines in the 10/22. Tons of fun!
Have you tried the HUSH .22LR subsonics? They run very well in all my .22's

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