I just had a SureFire MB338SS03 install by my local gunsmith. The barrel was too large in diameter and needed to be turned down to install the muzzle brake. I have another rifle with the same brake in it, and the brake screws right up to the shoulder with no gap between the brake and the barrel shoulder. The new install has about .25" gap between the base of the muzzle brake and the barrel shoulder (see picture). When I asked about the gap they told me it was installed correctly and that SureFire instructions indicate that a gap is required. I'm having doubts about that statement and think this is the ugliest install that I have ever seen. What do you think?