Since there have been several threads on muzzle brakes lately, I thought I'd ask a question that I've been wondering about...
Why does the sound level increase if you use one? Is it real or imagined (ie: sound blown back & to the sides instead of forward)? I've read about the efeects, but can't tell the difference at the range (I use heavy earmuffs). Anybody up on the science about it?

You have answered your own question.

Yes,

Depending on the type of brake, the 'blast' is redirected to 'control' the recoil and muzzle rise from a fired round.

If the brake doesn't redirect it back to you, but straight to the sides, you may not notice it as much.  However, your neighbor at the range certainly will.

But the overall total 'blast' is not increased.

good question.  i had the same one a while back and borrowed a sound level meter from the company i work for.  top of the line big bucks type of sound level meter, and with a fast enough rise time to catch peaks.  first thing i discovered when testing brakes vs. no brakes is that the sound is very directional.  directional being the key word.  the brake simply redirects the muzzle blast in directions other than they would go out the end of a simple regular barrel.  if you happen to be standing in that direction, the sound blast is noisier.  i believe it is somewhere between 7 to 10 dB's louder in most cases for a centerfire rifle.  that was the case when i tested about 6 different rifles with and without muzzle brakes.  it was an interesting day.  there doesnt really seem to be a lot of info available on the subject, but it is out there if you care to look hard enough....

That is the best analysis I've heard yet...


Good work Troy.
That's why I like this F*&#ing site.  You can be entertained and learn something too!!!

[beer]

DAMNIT NOW I'M WET!

Thanks guys. I knew it had to be something simple like that. I just didnt take the logical next step to relate the flash blast to the sound blast.

Whats really cool is when you have upward facing compensator ports in your brake and they build a nice angled tin roof over the firing line to reflect that noise back down to you.

Don't try the hose thing in your living room.It redirects the wife's  frying pan to your head.

Here you can see how blast redirects.. (scroll down.. link is in text)

[url]http://members.tripod.com/~ARthuri/[/url]

What I've always wondered about the sound redirection effect of brakes is this:  would a person down range a few hundred meters actually hear a significantly quieter report than from an unbraked rifle, and would it be harder for that listener to determine the exact direction from which the shot came?

At an off angle from the bore axis it would be a bit quieter but not much and no they would not have trouble locating where the shot came from becasue of the brake.

It is just a form of 'gain' like with radio waves and directional antennas.

There is no more total noise, it is just theat some is going to the sides and rear instead of the front.. You are actually making things quiter to the front where it does no good.

i have a AK break on mine and the sound gets thrown back on me. when my dad was down range (he was safe) he said it wasnt all that loud.