Originally Posted by ken snyder
The heavier the bullet for a cartridge the less the powder charge is and less recoil for rifle weight.
This isn't true. The heavier the bullet the more the recoil and a brake wont change that. That's physics. The higher the case capacity for a given bore size the the better a brake works and the smaller a bore is the better it works. They work by redirecting the gases so the more gas the better they work.
I haven't tested the shorter barrel theory but it might have more to do with the weight of the rifle with a shorter barrel rather than the brake being more effective. I'm a long barrel heavy rifle guy because I want the most accuracy I can get.
The direction of the ports does effect the recoil reduction and the noise. The shell hammer design used on the military 50 BMG's for years and years has ports that angle back heavily. It's not because they are quieter.