What are some of the brakes with the least back blast to the shooter? I've shot a few rifles that will blow you hair back with gases coming from the brake.
The muscle brake has its first port 90 degrees to help block the blast of the additional rearward angled baffles. My opinion only, but it offers a perfect mix of recoil reduction and minimal blast back for the shooter.
I have a JP on my AR and don't feel much back blast at all, but then again it's only a .223. I have the JEC on my .308 and feel a bit of back blast but not to much, its much stronger if you are on the side of it.
I'm running a VAIS brake on my HS 300wsm. It does a great job at reducing recoil and I've never noticed any blast coming back towards me, but like others are stating, the concussion and noise to the side are pretty bad. The guys at the range found it amusing last week when a carpenter bee happened to be right next to the muzzle when I touched one off. He was disintegrated.
I use the JP reducers on my 7mm rm and .308 rifles. They do an excellent job of reducing recoil, without putting any backblast on the shooter. They also do a pretty good job of keeping the dust down, when shooting in the dirt.
Before I started using cans I used a Jp "tactical" recoil eliminator. Worked awesome
The brakes that come on POF rifles work good too. I put one on my belt fed M16 to reduce muzzle rise and it works great but you do get some concussion.
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The way a brake works is by directing gas, lots of it, in the opposite direction it would have gone if the brake were not present.
So, basically, brakes will ruffle your hair.
Anything less than a 300 WM with 208+ bullets does not need a brake, in my opinion.
A good compromise between rear/side blast and recoil reduction is Steyr's brake model used on SSG 04 and 08.
The idea is the same as for the muscle brake mentioned above -- the first chamber is oriented forward to let most of the noise go where it belongs, the next two chambers actually brake.
Tested it on .308 and .338, bought it, love it (and spotters love it too).