I just had a 338LM built with a "fat bastard" brake from APA. In fairness, the rifle is a tank, but I was SHOCKED at the lack of recoil. And directly behind the rifle, prone, the blast and noise was not excessive (with ear protection).
Plus, they have a you tube video that I can watch about 12 straight times before it stops being entertaining.
I have a 300 WSM that I have grown to not enjoy shooting, and it effects accuracy. It will be wearing an APA brake soon.