Re: Muzzle brake or mercury tubes.
Anytime you add weight you'll reduce recoil and IMHO that's about all you get with mercury tubes so for example if you add a pound of tubes then the recoil will be reduced as much as if you slapped on a 1 pound scope or 1 pound heavier stock etc. In addition they can change the balance of your rifle. Besides I don't like the noise they make. Much better efficiency with a brake