I have Suppressor Design/Build Questions

[samsmix]

I am wanting a suppressor for my Walther P-22. I feel I have a good grip on how to go about this legally, and now I have design questions.
I will not acquire materials before receiving ATF approval

Thus far, as I am only using it on a .22, it seems like the simple mag light-solvent trap type seems easy and cost effective, but I have questions.

What sort of noise reduction can I expect from this with subsonic ammo?

The freeze plug baffles would be set at 90°. Would having them angled offer a greater reduction?

At this low blast level is there any advantage to running the can wet vs. running it dry?

As I lack machine tools, is there other low cost but effective ways to go about this?

[Mobuck]

"The freeze plug baffles would be set at 90°. Would having them angled offer a greater reduction?"

You really don't have much choice with freeze plugs.

[samsmix]

Since freeze plugs are cheap, I had an idea for punching the holes that would leave them stretched into an angled shape...maybe.

[Mobuck]

"Since freeze plugs are cheap, I had an idea for punching the holes that would leave them stretched into an angled shape...maybe."

It's not the shape of the hole, it's the fact that the flanges on the freeze plug are formed @90* to the center and nearly impossible to change that. I'm a shade tree mechanic and will say that freeze plugs are NOT malleable or "reformable" to any significant extent. They're made to be driven into a specific sized hole which the skirt seals tightly.

[samsmix]

I accept that you know what you are talking about and you are probably right...but I think I have a good idea...or a terrible one. Challenge accepted.

[Bartholomew Roberts]

I've shot my Silencerco Sparrow side by side with a DIY freeze-plug suppressor in .22LR. There was no distinguishable difference in noise to the naked ear. The Sparrow was shorter and much lighter however. The DIY suppressor was only $60 though

[samsmix]

Thank you Bartholomew Roberts. That's a good bit of info.

[samsmix]

So IF I can manage to angle the freeze plug baffles, will I gain a greater reduction in sound suppression?

[Sharkbite]

I doubt the effort would yeald much benefit. The Sparrow mentioned above has a monocore baffle with all kinds of twists and turns for the gas to follow. If that can was not any quieter then a standard freeze plug design, i doubt angling the plugs would effect the quietness of the can enough to be detectable.

[samsmix]

Probably not. Thank you for the info.

I did see a .22 shot with an un-baffled phoney can some years back. In .22 just having an expansion chamber seemed to offer a significant reduction.

Also, are the freeze plug types up to the blast of larger calibers? How do they hold up on a 9mm? .45 ACP?

Seems like a Ruger M-77/44 shooting .44 SPL might be a fun gun for a hog hunt. Not that we have hogs here in MT, but you know "have gun will travel" as long as there is a hint in it.

[Sharkbite]

22lr is REALLY quiet suppressed. My WarlockII on a Savage bolt gun is ridiculously quiet. Even my 22/45 with Stingers is quiet enough to not disturb the neighbors when im out thinning the rodent population

I dont know about freeze plugs and larger calibers. I just sent SilCo an email asking about 44spl and 44mag thru my Octane 45. Im doubting they give the nod to the Mag, but i think 44spl would be fine

[Sharkbite]

I got a response to my email

Octane 45 is rated 44MAG from a 16" barrel and 44spl has no barrel length requirement.

That can has a stainless baffle stack and an aluminum tube. Based on that, I would not hesitate to shoot 44 SPECIAL thru a freeze plug manufactured can with the appropriate bore diameter.

A 77/44 with a can on it sounds COOL. I might have to look into that idea

[silverstang23]

I'm not sure why you would want to build a "legal" DIY suppressor, especially a 22lr. You can purchase them from a reputable dealer for not much more ($250 gets your pick) than your $60 DYI. This doesn't even count your time. Now if you're trying to get around the stamp, different issue. PVC pipe and rubber bushings works pretty well for rodent control.

[rmh3481]

I think its a great idea to make your own muffler (suppressor). This is where new ideas come from. You should be able to get down to pellet gun sound. If your design is really good, BB gun sound.

When you read about 'wipes', what they were designed for was keeping military round nose ball ammo below the supersonic speed threshold. Any projectile that breaks the speed of sound will create a sonic crack. An alternate way to keep a projectile below supersonic is to bleed off pressure in the barrel. An example would be an integrally suppressed barrel and jacket for a 10-22. Holes are drilled through the barrel to keep the speed of the projectile below supersonic.

You can buy 22 ammo that is 'target grade', staying below the threshold of the sonic crack. The supersonic speed usually occurs around 1100 feet per second at sea level so whatever your elevation is will have some variance.

Good luck with the project.

[Elkins45]

You REALLY need to spend some time in the silencersmithing forum over at the Sikencertalk.com forum. There are some very good threads on forming freeze plugs for maximum suppression.

[dakota.potts]

Others have tried stamping baffles into an angle with a ball bearing and a press, but from what I've seen, they're rarely successful. If you're just looking to make one for experimentation, I would focus on getting them drilled to center. I haven't built one yet, but from my little bit of machine experience, that seems like a much more feasible option

[Theohazard]

Originally Posted by rmh3481

When you read about 'wipes', what they were designed for was keeping military round nose ball ammo below the supersonic speed threshold.

The primary purpose of wipes in modern silencers is to keep an ablative in the silencer instead of letting it all drip out the end. Modern wiped silencers like the Thompson Poseidon and Degroat Nano are ultra-compact designs intended to be fired wet, and the wipes help keep the liquid or gel inside the silencer. But the wipes barely slow the bullet at all, and they definitely won't make a supersonic bullet into a subsonic one.

Wipes can also be used to aid in the suppression process, older silencers often used a series of wipes that had to be replaced fairly often. These designs did slow the bullet a little, but not by that much; it takes more than a series of rubber wipes to reliably slow a bullet from supersonic to subsonic.

Now, I'm not saying that nobody has ever designed a silencer with wipes or other materiels that were intended to slow the bullet down, but in all the wiped silencers I've ever heard of the wipes barely slowed the bullet at all and were primarily used for suppression and/or holding in an ablative. And that's definitely the case with all wiped silencers currently in production.

The other method of bleeding gas through barrel ports is the primary way to keep bullets below the speed of sound. But virtually all the modern silencers I know of that use this method are .22 cans, and they're integrally-silenced rifle barrels.

Originally Posted by rmh3481

You can buy 22 ammo that is 'target grade', staying below the threshold of the sonic crack. The supersonic speed usually occurs around 1100 feet per second at sea level so whatever your elevation is will have some variance.

If you're shooting a .22 pistol, you don't need to bother with buying subsonic ammo; virtually all ammo will be subsonic out of a pistol. Even CCI Mini Mags are subsonic out of a pistol, and when shooting suppressed the difference in sound is barely noticable from .22 ammo that's specially intended to be subsonic.

[rmh3481]

Theo - What is an ablative?
https://www.google.com/search?q=abla...utf-8&oe=utf-8

Sionics were some of the first commercially available suppressors in the class iii world. The 9mm and .45 M10 designs used wipes to keep the bullet below supersonic. The Sionics High Standard 22 long rifle pistol also used wipes for the same reason whereas the M16/223 did not because it is not possible to keep the 223 below supersonic and yet retain any energy to the projectile.

[Sharkbite]

An "Ablative" with regards to suppressors is any liquid substance added to help with sound reduction.

Most common used is simple water. 5cc's or so squirted into a pistol can makes a big difference in sound. Wire pulling gel is also common.

DONT add anything to a Rifle can. The pressures are too high for added water or anything else.

Pistol pressures and 22lr are in the range that water will be fine.

[Theohazard]

Originally Posted by rmh3481

Sionics were some of the first commercially available suppressors in the class iii world. The 9mm and .45 M10 designs used wipes to keep the bullet below supersonic.

I'm not saying you're necessarily wrong, but I haven't been able to find any evidence online saying that's true. Everything I've found says the Sionics silencers used wipes for suppression; nothing says they slowed the bullet enough to be reliably subsonic.

Here's an excerpt from an article in Small Arms Review about Sionics. Nowhere in the article does it mention that the design was to slow the bullet down below subsonic:

"When originally established, Sionics was a company that supplied suppressors and similar items for covert operations by military and CIA type organizations. The suppressors that Sionics designed and sold consisted of a series of baffles and replaceable wipes to suppress muzzle blast. The life expectancy was six-months or 200 rounds before the unit’s efficiency deteriorated and the internals required replacement. A wipe replacement kit was available as a separate item."

In fact, there's an entire section about how Sionics developed subsonic 9mm ammo for use with their silencers. Why would they need to do that if their silencers already slowed the bullet to subsonic speeds?

"During the 1960s, Sionics launched an ambitious program to develop subsonic ammunition for their line of sound suppressors. [...] The program began by experimenting with the 9mm Parabellum cartridge, which has an average speed of 1,150 feet per second when loaded with a 115 grain bullet. The bullet’s velocity is increased with barrel length. No insurmountable problems were encountered developing subsonic 9mm ammunition and the task was accomplished by using a heavier bullet and lighter powder charge."

If you can find anything that says the wipes in their silencers were able to reliably slow a 9mm bullet to subsonic speeds, please link it. I don't mind being proven wrong, but I'd like to see some evidence first.