Rules for making a 12ga silencer

[motus]

The 2" ID/2.125" OD tube is the container. The conical washers are the baffles. If you port the barrel, you won't need the guide rods. You simply mount Grade 5 Titanium or 304 Stainless, or even 6061-T6 Aluminum Seamless Tubing. (Make sure that "seamless" isn't just edges rolled together to join them. That creates a weak seam that will split under pressure.)

If you use the ported barrel, the purpose of the baffles is to trap the higher pressures at the earlier compartments so that each stage has lower pressure gas to expand. This is called "dwell." Dwell allows the lower pressure end gasses to vent before the early sections dump their gas pockets back into the bore for venting to atmosphere. This "smooths" the exhaust to lower pressure over longer time resulting in less peak sound generated. It sounds more like a hiss than a bark w .22lr, but 12ga has far higher volume of gas to release.

Do you have a schematic of that ? I don't get how the conical washers will hold themselves inside the tube, nor what I will close it with.
Barrels alone cost half the weapon so I won't modify one, I'm trying to same money here or indeed I would have bought the salvo which seems to be the only thing available.
I'm also worried as to how to fix the silencer to the barrel since all 3 of my shotguns (Winchester SXP, Beretta 302, Baikal MP155) have that long cooling bar on the top and are not borred except one on the inside to receive chokes.

For your information I don't live in the USA but in France, here to make or buy gun accessories/parts you need the same authorisation as the gun it goes on. For SA and pump shotguns (which are limited in capacity) you only need a hunting licence or join a sport shooting club.
But home defence is badly seen. In France you're either a sport shooter / hunter or a dangerous man with weapons. There is no place to go to practice shooting with weapons that are not sport or hunting related, such as SA and pump shotguns. So you have to do it at home, or wherever you can but it's very noisy.
And mass produced silencers for shotguns, well they are already scarce in your country so imagine here.

[whiterussian1974]

THis was a plan I developed for .30-.50 cal rifle. But it works for 12ga since the pressures are far lower even though the gas volume in the barrel is fuller.

Just modify it to meet your needs.

If you want, just slide the outer tube back so that it's only around the barrel, then port the barrel w (12) 1/8" holes per inch.

Or keep the cones in front of the muzzle, and add the 9 guide rods that I mentioned. Look at how SilCo Salvo-12 does theirs. They can't easily do business in your country, so unless they have an International Patent, there shouldn't be any issue. Or just modify your plan so that it's a bit different than their Patent.

[fishman]

Without modifying the barrels, forget it. Unless you have a lathe and excellent machining skills, you can't make a screw in choke silencer adapter. Without modifying your barrels that's really your only option.

[whiterussian1974]

Use a set-screw against the cooling rib and the barrel's bottom. You still need a gasket or some other way to seal the gas from escaping to the can's rear. Even a wooden plug that blocks "most" of the gas from the rear chamber.

[fishman]

Use a set-screw against the cooling rib and the barrel's bottom. You still need a gasket or some other way to seal the gas from escaping to the can's rear. Even a wooden plug that blocks "most" of the gas from the rear chamber.

That would entirely block sight picture and render the gun near useless for applications requiring skillful aiming

[whiterussian1974]

Use a set-screw against the cooling rib and the barrel's bottom. You still need a gasket or some other way to seal the gas from escaping to the can's rear. Even a wooden plug that blocks "most" of the gas from the rear chamber.

That would entirely block sight picture and render the gun near useless for applications requiring skillful aiming

It would replace the Front Bead. The MOA shouldn't occlude an area larger than the pellet spread.

Or just add a new sight set to the top of the can. It will fit the same each time since the cooling rib will fix it's position from rotating.

If he needs that much precision while shooting suppressed, he probably needs a carbine.

[fishman]

i suppose a red dot sight could solve that problem too.

[Zombie1969]

Those shot guns are gonna do you a lot of good against the terrorists that have full auto assault riffles. I'd be the bad guy in France. Not a terrorist but screw being legal I'll be judged by 12 before I'm carried by 6 no thanks.

[whiterussian1974]

Those shot guns are gonna do you a lot of good against the terrorists that have full auto assault riffles. I'd be the bad guy in France. Not a terrorist but screw being legal I'll be judged by 12 before I'm carried by 6 no thanks.

I'm not sure that Juries work that way in France. Usually a Tribunal of Judges determines Guilt based upon Jury input. The Jury doesn't make Final Decision.

So judged by 3 instead of carried by 1, assuming cremation to save Crypt space.

[motus]

Those shot guns are gonna do you a lot of good against the terrorists that have full auto assault riffles.

Not sure if you're being ironic or not.
Just so you know, in France only the government's forces can have military weapons such as automatic assault riffles, nobody else. Citizens can at best get SA pistols (after 6 months in a club and a personal investigation) and .22lr SA version of riffle etc.
However 12ga shotgun is very popular because we have lots of hunters.

But lets keep this on topic please.

[a_canadian]

Ironic? Hardly. Have you read the list if weapons used by terrorists in the Paris attacks?

numerous semi-automatic handguns, automatic Kalashnikov rifles, a loaded M42 rocket launcher, 10 Molotov cocktails, 10 smoke grenades, a hand grenade, and 15 sticks of dynamite

That's from this page:
http://crimeresearch.org/2015/01/the-lo ... is-attack/
Not legal, but what do criminals care about legality?

[hardcase]

motus,

You have my sympathy.

Not to hijack your thread but I'm curious about the rules concerning firearms in France. Can you post a link? Also how did France get into such a sad state of affairs? You can send me a PM if you feel more inclined to do so.

Sadly, I can see our country heading down this same path.

[motus]

This wikipedia article seems like a good summary in English
https://en.wikipedia.org/wiki/Gun_laws_in_France
The detailed regulation is more complex, only gunsmith know it by heart.
For example SA shotguns can't have a magazine capacity of more than 2 or it becomes category B, same for pump action shotguns that can't have a barrel shorter than 45cm or have a smooth barrel.
Here's the website of the n°1 association of weapons owners http://www.armes-ufa.com/spip.php?article1408

The government does what it can to restrict more and more the rights to own weapons, but it's true that we never had the culture of weapons like the USA does. Historically people never defended themselves, they relied on the local lord to protect them, and nowadays on the police. It's only when they became soldiers for the king, or knights (before guns) that they could carry weapons.
Like I said personal defence is severely frowned upon, I don't know where it came from though, the government must have done some propaganda at some point in history.
In other words, in the mind of (most) people, they themselves cannot use weapons to defend themselves, they have to "call the cops". This I think dates from the French revolution and instauration of the Republic which believe or not gave less rights to the people. Yes you read right, we had more freedom under the kings' reigns. The Republic, which is now the 5th one, was the founding of what you call Big Brother. With the Republic everything is centralized and people cannot get anything (job, money, insurance, weapons, food, protection etc) outside of this system.

Even our law on self defence is problematic, it states that your response to aggression must be proportional. In other words if you don't want to risk being sentenced for injuring or killing an aggressor, you better let him rape / rob / murder you !

So that was concerning weapons in France, now regarding terrorist attacks and social situation of France, this is highly political (and off topic) so I will answer those who want by PM, with my opinion of course.

[hardcase]

motus,

WOW, I didn't know.

Also I want to compliment you on your use of English. I live in the southern part of the USA and Southern English is a bit different than what is common throughout the USA.