JP Muzzle Brake
About three years ago I had the opportunity at the Benchrest Club to shoot three rifles with the JP Muzzle Brake; a 30-378 Weatherby, 300 Weatherby, and a 300 Winchester. The gentleman who owned them father was an amateur gunsmith and installed the JP Brake on all the rifles.
There was virtually no recoil with the 30-378, a little with the 300 Weatherby, while the 300 Winchester had the most noticeable recoil. The bigger the cartridge, the less recoil in this comparison.
While the owner of the JP brakes was shooting next to me, the muzzle blast would blow my hair a little. Surprisely, the muzzle blast was not any louder than my unbraked 300 Weatherby. I was really surprised by lack of muzzle blast since I was around other type muzzle brakes including the Weatherby muzzle brakes, and IMO, the JP brakes was the "quietest". I was wearing ear muffs.