For our PHNX-MBS Muzzle Brakes we only need the Caliber and Two Measurements in order to custom machine the brake to fit your rifle.
Using a quality set of DIAL CALIPER or MICROMETER measure the diameter of the barrel at the muzzle and 1.625″ back from the muzzle. Recheck the diameters at several points around the barrel and submit your measurement as an average of these.
Please be as exact as possible to ensure we machine the correct diameter bore into your brake.
Your measurements need to be submitted in either thousandths of an inch – .###”
or hundredths of a millimeter – #.##mm