Integrally suppressed Vepr

[Hannibalbarca]

Here is my idea for an integrally suppressed Vepr.
10 the baffle length portion of the tube is 10 inches, maybe a bit more and it's also 3 inches in diameter and 316 stainless steel and the baffles are 416 ss.
The wall is .083
The "front cap" slides over the barrel.
It has four bolt threaded bolt holes as supper and will be tightend to keep it in place and also blue loctite.
I also plan to drill four small holes in this front cap where rods will go.
These rods will go into these holes and will be aligned to metal sections of the gun(the metal front sight) just as added support.
The tube will thread over the front cap and the end cap will thread around the threaded portion of the barrel.
Baffles will be cone cups, most likely 10 or 12 and no spacer since it really not needed for such low pressures and low gas volumes.

as for the barrel I have a couple of questions.
What's best?
1 to machine out lines down the barrel, say 8, so 8 spaces and 8 metal portions
2 or to drill out holes instead.
I'm thinking holes but ones that are angled down meaning if you were to be looking down the barrel this is the position you would be drilling from at an angle so the gasses are ejected to the front.
<<<<
00000-------
<<<<

0 = gun
- = barrel
< = drilled holes and direction of gas escaping.

Another question I have is would it be better to weld the front cap to barrel or is my idea of using four bolts pushing against the barrel(with loctite) and further support from the rods good enough? The gas is being ejected straight forward so I don't think I really need the rods as the whole thing is being pushed forward by these gas streams but I could go with oppositely angled drilled holes.
Also these holes or these machined out lines would start half an inch from the end of the front cap and end an inch from the from the threads at the end of the barrel.

is this a bad design? Anything wrong with structural integrity? How about db levels? Can I expect 133db with regular birdshot?

[a_canadian]

I have zero experience with suppressing a shotgun, but if the 12" Salvo averages 21.2dB reduction I doubt something like you're describing is going to surpass that.
http://www.capitolarmory.com/silencerco ... essor.html

[fishman]

a picture is worth 1000 words

[doubloon]

... Can I expect 133db with regular birdshot?

If you stand far enough away from it sure.

[a_canadian]

Isn't a 12g somewhere around 160dB, or louder? I haven't heard of any add-on shotgun cans dropping more than 25dB or so. The hushpowers maybe, drilling a bunch of holes along the barrel and sticking strictly to subsonics. But not a muzzle can. And set screw attachment sounds dicey. Probably just blow the thing downrange after a mag or two.

[3strucking]

... Can I expect 133db with regular birdshot?

If you stand far enough away from it sure.

lol

[Hasdrubal]

I was working on something similar for a Saiga 12 for a while, put it on hold for other projects because it wasn't working very well.

I used the factory thread protector pressed into an aluminum front endcap, because I wasn't sure if fine threads in Al would hold up. As it is, the cap starts to slide off after 20 rds or so, I either need to use some Rocksett or come up with a new cap. It's a tight enough fit that I don't think set screws will work, since you will have a lot less surface area for friction at the screw tips.

I went with six skirted cone baffles, and with a ring of staggered holes drilled in the barrel between baffles. At first the holes were drilled at 90 degrees straight into the barrel. Even after deburring them, they shaved off a fair amount of material with each shot. I redrilled each hole slanting back, and it fixed that problem.

Unfortunately, the sound reduction is not very good so far. It is clear there is a change in volume, but it's not hearing safe. My next steps when I get back to it will be to continue increasing the number of holes in each chamber, and to add steel wool. I figure since there's so much barrel still there, the turbulence you would normally get from cones isn't happening, and it's more like a glass pack car muffler than a rifle type silencer.

[Hannibalbarca]

I was working on something similar for a Saiga 12 for a while, put it on hold for other projects because it wasn't working very well.

I used the factory thread protector pressed into an aluminum front endcap, because I wasn't sure if fine threads in Al would hold up. As it is, the cap starts to slide off after 20 rds or so, I either need to use some Rocksett or come up with a new cap. It's a tight enough fit that I don't think set screws will work, since you will have a lot less surface area for friction at the screw tips.

I went with six skirted cone baffles, and with a ring of staggered holes drilled in the barrel between baffles. At first the holes were drilled at 90 degrees straight into the barrel. Even after deburring them, they shaved off a fair amount of material with each shot. I redrilled each hole slanting back, and it fixed that problem.

Unfortunately, the sound reduction is not very good so far. It is clear there is a change in volume, but it's not hearing safe. My next steps when I get back to it will be to continue increasing the number of holes in each chamber, and to add steel wool. I figure since there's so much barrel still there, the turbulence you would normally get from cones isn't happening, and it's more like a glass pack car muffler than a rifle type silencer.

Have you had any success in greater sound reduction?
Also I have decided to go in a different direction.
A 12 inch steel gun thread adapters Napa 4003 tube
2 cones at the end and behind that would be thick steel wool and shoe eyelets.
A second 7 inch aluminum tube using a Napa 4003 metal fuel filter element. This would help guide the wad and act as a baffle. It would be press fitted between two caps.
I need a Napa 4003 m22x.75 coupling cap though.

[Enfield577]

Hi, I have just finished working on suppressing a 410, it proved quite hard to do, to get the level of suppression that I wanted.

I ended up going multi chamber, using shoe eyelets in the first chamber, then exhaust packing and finally a small suppressor with M baffles built on to the front.

However there is massive porting to the barrel so that you can use standard high velocity ammo and drop it down to sub sonic levels, this now runs on up to 3" shells and is extremely quiet, sounding like a loud hand clap. You will have to work some development to get a 12 G similar but this should give you some ideas.

[doubloon]

Hi, I have just finished working on suppressing a 410,
...

A very nice build it is and the thread where the talented craftsman [you] took a solid engineering approach to the project from start to end was fun to follow.

[Enfield577]

Hi, I have just finished working on suppressing a 410,
...

A very nice build it is and the thread where the talented craftsman [you] took a solid engineering approach to the project from start to end was fun to follow.

Thanks doubloon, I must refresh the build thread as took the photos out a while ago when I was looking at patent options, proved too expensive for my little hobby job.......went down the trade mark route instead hence the "FSS"

Cheers

[Hannibalbarca]

Hi, I have just finished working on suppressing a 410, it proved quite hard to do, to get the level of suppression that I wanted.

I ended up going multi chamber, using shoe eyelets in the first chamber, then exhaust packing and finally a small suppressor with M baffles built on to the front.

However there is massive porting to the barrel so that you can use standard high velocity ammo and drop it down to sub sonic levels, this now runs on up to 3" shells and is extremely quiet, sounding like a loud hand clap. You will have to work some development to get a 12 G similar but this should give you some ideas.

I’d acrually want to go with a much wider tube.
6061 aluminum and 7075 end caps
3” OD and 2.75 ID 12 inches
Will use just copper or brass wool in it.
The internal volume will be similar to the salvo 12 which gets magnum 3 inch buck shot shells at 137 dB.

[Enfield577]

Hi, I have just finished working on suppressing a 410, it proved quite hard to do, to get the level of suppression that I wanted.

I ended up going multi chamber, using shoe eyelets in the first chamber, then exhaust packing and finally a small suppressor with M baffles built on to the front.

However there is massive porting to the barrel so that you can use standard high velocity ammo and drop it down to sub sonic levels, this now runs on up to 3" shells and is extremely quiet, sounding like a loud hand clap. You will have to work some development to get a 12 G similar but this should give you some ideas.

I’d acrually want to go with a much wider tube.
6061 aluminum and 7075 end caps
3” OD and 2.75 ID 12 inches
Will use just copper or brass wool in it.
The internal volume will be similar to the salvo 12 which gets magnum 3 inch buck shot shells at 137 dB.

This is only 38 o/d 3 wall (1 1/2 x 1/8) but is 410, as you say must go way bigger for 12G, though I will try 2" but go steel tube thiner wall. I think you will find that any type of wool will crush down real quick....I tired that early one, started getting much louder after only 4 or shots. 137 db is quite loud still, I just shot a pest tonight from the dining room window, the wife in the lounge next door said she did not hear the gun.....it is really quiet, say like loud hand clap but a duller sound...I shot af four birds about 20 yards away, they did not fly off and I got a second shot off.

[Hannibalbarca]

Hi, I have just finished working on suppressing a 410, it proved quite hard to do, to get the level of suppression that I wanted.

I ended up going multi chamber, using shoe eyelets in the first chamber, then exhaust packing and finally a small suppressor with M baffles built on to the front.

However there is massive porting to the barrel so that you can use standard high velocity ammo and drop it down to sub sonic levels, this now runs on up to 3" shells and is extremely quiet, sounding like a loud hand clap. You will have to work some development to get a 12 G similar but this should give you some ideas.

I’d acrually want to go with a much wider tube.
6061 aluminum and 7075 end caps
3” OD and 2.75 ID 12 inches
Will use just copper or brass wool in it.
The internal volume will be similar to the salvo 12 which gets magnum 3 inch buck shot shells at 137 dB.

This is only 38 o/d 3 wall (1 1/2 x 1/8) but is 410, as you say must go way bigger for 12G, though I will try 2" but go steel tube thiner wall. I think you will find that any type of wool will crush down real quick....I tired that early one, started getting much louder after only 4 or shots. 137 db is quite loud still, I just shot a pest tonight from the dining room window, the wife in the lounge next door said she did not hear the gun.....it is really quiet, say like loud hand clap but a duller sound...I shot af four birds about 20 yards away, they did not fly off and I got a second shot off.

What would you reccomend to use instead of the copper wool? Im looking for something cheap.
I feel that shoe eyelets would be too heavy and also would get into the barrel ports.

[doubloon]

...
I feel that shoe eyelets would be too heavy and also would get into the barrel ports.

Brass eyelets come in different sizes, 1/2" are easy to find. How big to you plan to make your barrel ports?

[Enfield577]

I tried all sorts of mesh, packing, scrubbing pads, wool, the lot it all crushed down (that was at the high pressure end, starting about 2" past the end of the chamber).

I ended up going to 1/8" dia holes, the eyelets were around 3/16" so no issues there, if you find something else that work let me know, would be very interested.

Oh I would say, weight was not really an issue you can see I just filled with eyelets towards the rear where the big blast is.

Cheers

[Hannibalbarca]

...
I feel that shoe eyelets would be too heavy and also would get into the barrel ports.

Brass eyelets come in different sizes, 1/2" are easy to find. How big to you plan to make your barrel ports?

1/4, maybe 1/3.
Most likely increase the size as I go up the length but 1/3 would be the biggest.
Shoe eyelets would be very heavy especially with the amount of volume I need to fill up with a 12 inch 2.75 ID tube.
Maybe use eyelets in the rear and follow by a lot of wool?

[Hannibalbarca]

I tried all sorts of mesh, packing, scrubbing pads, wool, the lot it all crushed down (that was at the high pressure end, starting about 2" past the end of the chamber).

I ended up going to 1/8" dia holes, the eyelets were around 3/16" so no issues there, if you find something else that work let me know, would be very interested.

Oh I would say, weight was not really an issue you can see I just filled with eyelets towards the rear where the big blast is.

Cheers

I was thinking of using washers and having an ar15 flat wire stainless spring hold them in place but the barrel of vepr is .13 too big it seems.
Maybe have wool in between these washers as well? Still could work but would be expensive since the washers are 14 dollars and you’d need to find a spring to use.

[Enfield577]

I tried all sorts of mesh, packing, scrubbing pads, wool, the lot it all crushed down (that was at the high pressure end, starting about 2" past the end of the chamber).

I ended up going to 1/8" dia holes, the eyelets were around 3/16" so no issues there, if you find something else that work let me know, would be very interested.

Oh I would say, weight was not really an issue you can see I just filled with eyelets towards the rear where the big blast is.

Cheers

I was thinking of using washers and having an ar15 flat wire stainless spring hold them in place but the barrel of vepr is .13 too big it seems.
Maybe have wool in between these washers as well? Still could work but would be expensive since the washers are 14 dollars and you’d need to find a spring to use.

I tried a heavy spring with washer to take the blast, it lasted a few shots and the spring was all beaten up, crushed down and distorted. The spring was heavy duty with wire about 0.1".