I have a unique idea that I think would work fairly well either in a 12 gauge breachloader or a 26.5mm flare gun.

You guys may have seen the .22lr sub-caliber inserts for military flare guns, I think they also make various sub caliber inserts for 12 gauge shotguns.

Would it not be all that hard, with a form 1 of course, to build an integrally suppressed rifled .22lr insert. I'm thinking it would have some considerable length to it but it would probably work quite well.

Good idea?
Are there any potential issues I'm overlooking here?

dark2023 wrote:I have a unique idea that I think would work fairly well either in a 12 gauge breachloader or a 26.5mm flare gun.

You guys may have seen the .22lr sub-caliber inserts for military flare guns, I think they also make various sub caliber inserts for 12 gauge shotguns.

Would it not be all that hard, with a form 1 of course, to build an integrally suppressed rifled .22lr insert. I'm thinking it would have some considerable length to it but it would probably work quite well.

Good idea?
Are there any potential issues I'm overlooking here?

Only issue I can see will be that it is going to be non-concentric to actually fire the cartridge since the 22lr is a RIMfire.

BTW it has been done before.

Only issue I can see will be that it is going to be non-concentric to actually fire the cartridge since the 22lr is a RIMfire.

I realize that the baffles will have to be offset, but if it works for the osprey it'll work for my purposes.
Hopefully it will still work as well if I go with a ported barrel more akin to a 10/22 integral.

BTW it has been done before.

Are there any links or pictures of this?

Not a suppressor inside a shotgun, but this project from Dr.K should get you started:
viewtopic.php?f=10&t=123640

That is quite close to what I am proposing. It would seem that in that thread someone also suggested my exact idea.

Seeing as how this would be a form 1, hopefully I will be able to e-file once I get the funds together and bypass the dullest part of everything, the 9 month wait period.

I'm thinking I might go with something a little more substantial than .22 now though, maybe .38 or 300 blackout.
Any idea how well that might work? Any suggestions as to rounds I might want to look into?
I'm hoping to get this as theoretically quite as possible, while still having worthwhile performance. Please keep in mind that I'll have to keep my suppressor body under .74 inches total diameter, so I cant be using something with ridiculous pressures.

This idea is something I'm really deeply considering now, I have access to a machine shop and a fairly good understanding of how suppressor technology works. The only thing really holding me back is not having the expendable funds needed.

dark2023 wrote:That is quite close to what I am proposing. It would seem that in that thread someone also suggested my exact idea.

Seeing as how this would be a form 1, hopefully I will be able to e-file once I get the funds together and bypass the dullest part of everything, the 9 month wait period.

I'm thinking I might go with something a little more substantial than .22 now though, maybe .38 or 300 blackout.
Any idea how well that might work? Any suggestions as to rounds I might want to look into?
I'm hoping to get this as theoretically quite as possible, while still having worthwhile performance. Please keep in mind that I'll have to keep my suppressor body under .74 inches total diameter, so I cant be using something with ridiculous pressures.

This idea is something I'm really deeply considering now, I have access to a machine shop and a fairly good understanding of how suppressor technology works. The only thing really holding me back is not having the expendable funds needed.

Dealing with the .74" bore is what will be your biggest hurdle.

Personally with that small a suppressor tube I wouldn't waste a stamp on anything bigger than 25acp.

This is a very cool idea and I've been thinking on it more overnight. I see 2 issues with having a suppressed sub-caliber insert completely inside a shotgun barrel.

1. Volume, or lack thereof. As Bender pointed out, with anything more than .22 or .25 there will likely be problems controlling the gas volume with so small a tube diameter. I suppose if you kept your barrel length short enough and had a crap ton of baffles, you could adequately suppress 9mm in a very long shotgun barrel.

2. Engraving/Marking. Since we have to put the maker's name, city, state, caliber and SN on the tube; you either have to engrave the shotgun barrel, or have an engraved tube that slides into the barrel (further reducing volume).

1. 2a. If you choose the first option, you can only have the one caliber insert and have to get written permission to take your shotgun out of state. Extra inserts could be construed as "suppressor parts", which are verbotten.
   2b. If you choose the second option, the engraving has to be visible, so it will have to stick out of the end of the barrel.

You may want to consider having the sub-caliber insert long enough for a threaded end to stick out and put a screw on suppressor on it. This would solve #1 and #2, but isn't as slick as a suppressed insert. You could, however, then make it in 300 BLK - just for giggles.

-Steve

srs wrote:This is a very cool idea and I've been thinking on it more overnight. I see 2 issues with having a suppressed sub-caliber insert completely inside a shotgun barrel.

1. Volume, or lack thereof. As Bender pointed out, with anything more than .22 or .25 there will likely be problems controlling the gas volume with so small a tube diameter. I suppose if you kept your barrel length short enough and had a crap ton of baffles, you could adequately suppress 9mm in a very long shotgun barrel.

2. Engraving/Marking. Since we have to put the maker's name, city, state, caliber and SN on the tube; you either have to engrave the shotgun barrel, or have an engraved tube that slides into the barrel (further reducing volume).

1. 2a. If you choose the first option, you can only have the one caliber insert and have to get written permission to take your shotgun out of state. Extra inserts could be construed as "suppressor parts", which are verbotten.
   2b. If you choose the second option, the engraving has to be visible, so it will have to stick out of the end of the barrel.

You may want to consider having the sub-caliber insert long enough for a threaded end to stick out and put a screw on suppressor on it. This would solve #1 and #2, but isn't as slick as a suppressed insert. You could, however, then make it in 300 BLK - just for giggles.

-Steve

Why would you need permission to take your shotgun out of the state? Silencers are immune to that req.

The inner tube would have to be engraved, it doesn't have to be visible if its removable, no different than a SD type setup on an AR.

Inserts would NOT be considered silencer parts unless it was integral to the suppressor, then it would be. No different than any other host out there.

Bendersquint wrote: Why would you need permission to take your shotgun out of the state? Silencers are immune to that req.

The inner tube would have to be engraved, it doesn't have to be visible if its removable, no different than a SD type setup on an AR.

Inserts would NOT be considered silencer parts unless it was integral to the suppressor, then it would be. No different than any other host out there.

I have learned new things today. I thought you had to do a Form 20 for all NFA items and that all engraving was now mandated to be visible.

srs wrote:

Bendersquint wrote: Why would you need permission to take your shotgun out of the state? Silencers are immune to that req.

The inner tube would have to be engraved, it doesn't have to be visible if its removable, no different than a SD type setup on an AR.

Inserts would NOT be considered silencer parts unless it was integral to the suppressor, then it would be. No different than any other host out there.

I have learned new things today. I thought you had to do a Form 20 for all NFA items and that all engraving was now mandated to be visible.

It's all in the NFA Handbook.

I see no reason why I could not laser engrave the insert, as stated, as long as it's removable there is no difference between that and other setups which cover or otherwise obscure the visibility of a suppressor.

I may just try to add a simple suppressor to a 12 gauge sub-caliber insert. That would be the cheapest thing possible. E-file for the form 1, and then buy an already existing .22lr subcaliber insert and add a suppressor to it. The only issue here is that I wanted to try a ported barrel, integral type suppressor, however adding a suppressor to an already existing rifled inset will just be a basic baffle stack and tube welded to the end.

Is the suppression of a ported barrel style suppressor (think integral 10/22 or De Lisle) noticeably better than a K baffle type suppressor, does the extra rifled barrel length have a serious effect on velocity or accuracy. (or does porting reduce velocity)

dark2023 wrote:I see no reason why I could not laser engrave the insert, as stated, as long as it's removable there is no difference between that and other setups which cover or otherwise obscure the visibility of a suppressor.

I may just try to add a simple suppressor to a 12 gauge sub-caliber insert. That would be the cheapest thing possible. E-file for the form 1, and then buy an already existing .22lr subcaliber insert and add a suppressor to it. The only issue here is that I wanted to try a ported barrel, integral type suppressor, however adding a suppressor to an already existing rifled inset will just be a basic baffle stack and tube welded to the end.

Is the suppression of a ported barrel style suppressor (think integral 10/22 or De Lisle) noticeably better than a K baffle type suppressor, does the extra rifled barrel length have a serious effect on velocity or accuracy. (or does porting reduce velocity)

You can engrave the insert if the complete insert is the silencer, if the insert is PART of the silencer and the barrel is the "sleeve" then the barrel would need to be engraved.

You can engrave the insert if the complete insert is the silencer, if the insert is PART of the silencer and the barrel is the "sleeve" then the barrel would need to be engraved.[/quote]

The insert would be fully self contained, that way itll work in any breach loading 12 gauge. Also I feel like the prescion required to install baffles directly inside a shotgun barrel would be beyond my capabilities. Its much easier to make the insert and suppression tech all one peice, though hopefully user servicable.