Just got my Bushy Dissipator back from Wilson with it's new Combat Muzzle brake.  Took it to the range and the point of aim was about 12 inches lower at 100 yrds then it was prior to the attachment of the brake.  Grouping was still pretty much the same, but had to set the rear sight way up.  My front sight was additionally frozen, which it wasn't before the conversion, so I had to move the rear sight.  Has anyone else experienced this?