OK, I've read that the Flaming Pig and some similar designs are designed to generate a bit more pressure for functioning on short barrels.  Also, while not reducing noise, seem to focus the noise straight out from the shooter, technically reducing the volume of noise to the shooter, w/o being considered a silencer.



Is this true?

Does the common AR upper with the 11.5 inch barrel and the permanent 5.5 inch "flash hider" potentially do the same thing?  

After the bullet leaves the rifling at 11.5 inches, it now enters the flash hider.  The interior of the flash hider, being larger in diameter than the .223 barrel, would allow more space and room for unburned powder to burn, and I'm guessing cool, before it exits at the end of the 16.5 inch tube.  



Does this tend to focus noise away from the shooter as well?

i've only shot one 11.5 with 5.5, and it seemed louder to me than a comparable 16" so i'm going to guess no.

I don't own an SBR, but for some reason I always seem to wind up shooting next to guys who do. Im not sure about noise levels, but there is one definate difference between the Noveske Fire Pig and other muzzle devices: the blast.

Next to most muzzle devices, it almost feels like your getting slapped. The noveske does a REALLY good job of 'focussing' that concussion down range. I'd compare shooting next to a noveske on a 10.5 to shooting next to somebody with a 16" or even a 20". Shooting next to a 10.5 with just a birdcage is like being next to someone with a .50BMG.

I would love to see what's going on internally with that thing, but don't have a need to purchase one.  

I believe there is some type of cone in it...

 

It's a "knock off" off a FH from a Krink.  On shorter guns it add backpressure.

Anyhow, if you took your moderated 11.5, and cut the end flat, so there were no ports, your sound would head outwards as well.