Sonic Reduction System

[jmar]

Is there such thing as a gun that ports gasses from the barrel or chamber to reduce the velocity of a round from sonic to subsonic? There must be, i'd just like some examples for research purposes. Thanks

 

[edwardware]

Can't think of a design that does that on purpose. For one, it'd be wasteful; burning propellant just to vent the gas to the atmosphere isn't efficient. For two, it'd be really loud unless you ran the gas through a muffler, and that's basically a suppressor. . .

 

[tootall]

Look up the MP5SD of many 22 integral suppressed barrels. they use a single to multiple ports PROIR to the muzzle and start of the suppressor baffle stack. This bleeds gas pressure to bring a supersonic round below 1100fps.

 

[lysanderxiii]

Look up the STEN Mk IIS and the L34A1.

Both based on Delise's patent of 1942.

 

[jmorris]

That's the point behind these ports. Takes a regular normally super sonic 115gn load and make it subsonic.

It keeps them from having to buy "special" subsonic ammunition. FWIW my 147 grain 9mm load happens to be subsonic while also being a "max" load. The ported barrel of the MP5SD is the only gun I have used them in where they won't cycle the action.

 

[Jim Watson]

And it also considerably reduces the power. Bleed 200 fps off a pistol bullet and you haven't got a whole lot left. But it simplifies the supply chain.

 

[lysanderxiii]

In 1944, with war going on it makes sense to use a ported barrel, in 2017, just buy 147 grain subsonic 9mm....