I'm sure this is a hashed out subject, but I've searched the archives and unable to find any quantitative comparisons of the myriad types of muzzle brakes out there. It would be nice to see actual test results of percent reduction and decible increase for the popular type out there. There's no end of antidotal reviews, but no hard results.
Think you will find that "hard" data is hard to come by. Second, you list the most marketable ones that cater to select markets or are most commonly hyped. Think you will find some just as good and much cheaper. Noise reduction is just one aspect and often the least important.
You listed most of the better ones. As general rule the chamber brake style (Vais, Answer, Tooley, Myer, Harrels etc) seems to give the best recoil reduction with minimal blast.
Have shot and seen shot every brake out there and I go to ones that limit the concussion whereas the KDF style seem to make it worse.
You can spend $260-400 for some or you can buy a Harrels for $30 and $70-100 for installation. Either way, you are still going to have to wear muffs/and or plugs and I challenge anyone to "hear" 2-5 db difference when it is in the 140+ range to start with. That is before you figure the concussion itself.
I have several Holland, Tooley, Harrels that work very well all are under $150 installed in most cases. Personal opinion there is a lot of "hype" and big time markups in brakes with some smiths.
Right now, for the money the Holland and Harrels offer the best deal. The Holland is $60-90 and the Harrels is only $30.
Will any of them make your gun "shoot" more accurately, NO more than any device that will change the barrel harmonics and bring you closer or further from a sweet spot.
I have a PGW break on my twolf. It reduces recoil so much it feels like I'm shooting my 15 lb 308 win. It also directs the gases directly to the sides so it won't kick dust in your face. I will kick dust in a neighbors face though. [img]images/icons/wink.gif[/img] Plus it is a handsome break. It is pretty loud like any other break but you get used to it pretty fast (I wouldn't shoot it without earplugs though)
The primary purpose of any muzzle break is to reduce felt recoil - understood.
Having worked in the aircraft industry I also feel that little holes - or more correctly smaller total port area - will drive up the noise level as the gases escapes at a higher velocity. Low velocity = lower noise output, higher velocity = higher noise output. Important point here is total forward thrust against the body of the break is what provides the recoil reduction.
Low noise is one of the primary reasons you see larger engines on the big jets (that and fuel efficency), the gases are slowed down which makes for quieter engines, but total thrust remains the same. I also compare a muzzle break to the reverse thrusters you see at the back of a 737 engine. They can be very noisy when engaged.
So enough of the rambling, what makes sense to me as to what design makes an efficent brake is large total port opening - for lower noise and maximum redirection of gases for maximum forward thrust.
There is one that intrigues me, the Op's unit. Any experience out there on that unit?
The best one in reduced felt recoil bar none is any on of the clam shell type brakes. For normal calibers it is the OPS INC. I put and shot them on Lapuas, RUM's, 300 Win Mags, WSM.... you name it they are one of the best if not the best.
The other's are good some more so than others, some reduce recoil and some are louder than hell.
There is really no easy way to compare them because every rifle weighs more or less than the next, certain stocks handle recoil better than others...the list goes on.
My question would be what are you putting it on-rifle specs? And what do you want it to do?