A 'not moderator'; reduced pressure directional blast attenuator for 22lr?

[brown dog]

Playing with my 22, I'm quite struck by the amount of gunge that gets blown back onto the bolt face etc. I've convinced myself that this is due my moderator causing the increased barrel pressure to dwell slightly longer than would be the case with a muzzle brake or 'naked' muzzle.

 

I'm sure I've seen devices rather like open-front hybrid moderator/muzzle brakes, not classed as moderators, that direct noise toward the tgt (and away from the shooter) -and which, I presume, won't cause the same pressure dwell.

 

Ring any bells with anyone?

[ds1]

Called a pig brake I think in the USA. Also made a n cz - have one on my 9mm AR with 6.5 inch barrel. Same principle - direct blowback, works well with no undue crap in the chamber or lower. Think of it as a single chamber with a cone.

 

https://drive.google.com/open?id=0BxVRZotMscwfRjI4NHFVMlpHOTA

 

https://drive.google.com/open?id=0BxVRZotMscwfT3huX1gxeEExTGM

 

OTOH you could use a still air tube - did that on my dta 16 inch barrel and it was effective at directing noise down range.

[brown dog]

David, I have it in my head that those single cone brakes are designed to intensify barrel pressure on short barrels (?)

 

Still air tube? Something like this? (Just bodged it together to try; empty SAK tube, normal AR15 flash thingy, polymorph, just waiting for it to harden!)

[brown dog]

David, I have it in my head that those single cone brakes are designed to intensify barrel pressure on short barrels (?)

Still air tube? Something like this? (Just bodged it together to try; empty SAK tube, normal AR15 flash thingy, polymorph, just waiting for it to harden!)

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Damn! 2 shots with that hurt my ears more than the AR15 muzzle thingy on its own!

[brown dog]

Back to the drawing board. Different idea hardening:

[brown dog]

Nope.

[ds1]

Matt, google vz59. They use a cone with no chamber. I will see later if I have some video of my vz59 being shot. I have a spare cone lying around. I could measure thread size. if it is what you are trying to do I will post to you.

 

[brown dog]

Thanks, David, love to give it a go, but 99% it'll be metric!

 

Just tried this with and without flash thing - I think, if anything, it intensified the noise!

[brown dog]

I think, next idea will be empty SAK on a nut (rather than flash thing) and a scouring pad rolled inside the tube.

[ds1]

The only other thing that I have tried the vz59 cone on is an AK47. This was to reduce flash for NVD use. It seemed to work well enough.

 

I think the SAK tube is very workable if you play around with internal coatings - something rubberised or maybe foam pipe lagging tube. May not be durable but worth a try if you use an alloy ring spacer for the first inch or two to absorb most of the blast.

[EMcC]

If you can get your hands on a Husher moderator, they are just a hollow can so could be used without the front end on or with the front end on but the exit hole enlarged maybe ?

I have one with a 1 x 20 unf thread that you would be welcome to play with for a while until you get sorted.

[Gandy]

I've no idea if you could draw a parallel for your needs but, would the muzzle of a Bren gun give you an idea of profile and shape etc?

[Shuggy]

You might want to try a 'bloop tube'. Your open ended SAK was the right approach, but probably too short. Most commercial bloop tubes are at least 6 inches long. For your application, I would try the longest tube that is still practical in length.

[brown dog]

You might want to try a 'bloop tube'. Your open ended SAK was the right approach, but probably too short. Most commercial bloop tubes are at least 6 inches long. For your application, I would try the longest tube that is still practical in length.

Thanks, Shuggy. What sort of diameter would you suggest for this application?

[Shuggy]

Thanks, Shuggy. What sort of diameter would you suggest for this application?

Most are sized to fit 0.22 target barrels, so about 22mm diameter by 150mm long? 200mm long might be OK size wise.

[MrCetrizine]

My Feinwerkbau 2700 came with such a device. It's primarily to push the foresight tunnel further forward increasing the sight radius. It does however alter the report of the rifle considerably from the shooters perspective. Without it, there is the usual snap sound and with it, it's more of a quiet poink noise.

Mine is 180mm long with a 22mm diameter.

 

A friend has one on his Anschutz and because one of his clubs requires moderators and he rightly refuses to screw cut a £3000 match barrel, he sticks a couple of cleaning patches over the front with tape. These act like the wipes you get in a Welrod and lessen the noise to the point where his club is OK with it and it doesn't affect accuracy. They need replacing after 20 or so shots.

[brown dog]

Most are sized to fit 0.22 target barrels, so about 22mm diameter by 150mm long? 200mm long might be OK size wise.

 

My Feinwerkbau 2700 came with such a device. It's primarily to push the foresight tunnel further forward increasing the sight radius. It does however alter the report of the rifle considerably from the shooters perspective. Without it, there is the usual snap sound and with it, it's more of a quiet poink noise.

Mine is 180mm long with a 22mm diameter.

 

A friend has one on his Anschutz and because one of his clubs requires moderators and he rightly refuses to screw cut a £3000 match barrel, he sticks a couple of cleaning patches over the front with tape. These act like the wipes you get in a Welrod and lessen the noise to the point where his club is OK with it and it doesn't affect accuracy. They need replacing after 20 or so shots.

 

Thanks, both !