I have a MB on my 45-120 BC...and most of my other large bore cannons, including my latest 510 Makatak, a Rigby case blown out and shortened 0.050". What has been said over and over again about noise is true, more or less...all the brake does is redirect the sound to the sides and redirect the gas velocity energy the same way, which is roughly 30-50% of the recoil energy, again depending on the SIZE of the case and the amount of powder that is burned...it doesn't matter what size the caliber as much as the AMOUNT of powder burned...
I don't have ANY problems with noise as long as I wear ear protection, it doesn't matter WHAT I shoot...with or without a brake...and you SHOULD be wearing both ear plugs AND ear muffs when shooting at a range.
Anyone shooting a rifle with a MB should go to the farthest end and take along their own set of easily made baffles, it doesn't take much to redirect the sound away from other shooters.
MB's are like any other problem...there are simple solutions if you want to bother with solving the problem.
A MB DOES make a difference when shooting the 720gr T-Rex slugs over a full case of powder in my 45-120 BC, and the same with ANY of my big boomers, 375 H&H, 416 Taylor, 458 WM all with slugs on the heavy end and full cases of powder.
Anyone seeing a brake on a rifle and the placebo effect goes into full speed and whatever amount of noise produced is multiplied at least 100 times....
the same with ANY noisy object like loud motorrcycles, trucks, ATV's or lawn mowers early on Sunday morning.
Going over the pressure level of the NEF just because you have a MB to reach some specific level of efficiency is totally bogus...you NEVER overload beyond the capability of the receiver MB or not...where did that come from?
?? Having a MB on any rifle DOES NOT, in and of itself, cause ANY KIND of pressure problem. The MB is basically only a device to redirect the powder gas jet.
Not to change the subject... but has anyone doen any wildcatting with the 500 S&W...like rechambering to the 499 HE or use one of the rimmed 50 cal cases??? I still have it in the back of my mind to do one, but I want at least a 30" bbl...that stubby 22" jobby would really reduce the velocity, at least that's what the number crunching indicates...reality is always another matter.
Luck