Walker Defense makes some of the best muzzle brakes around. At least in my opinion. I have had the Walker Defense NERO 9 muzzle brake for over a year now. Is it the best muzzle brake I have used? Yes, at least in 9mm. The NERO was also used on a 357 magnum lever gun, which is not a typical use for this muzzle brake. It also performed great on the 357. So why is it so good? You will have to read the rest and find out.