Building a Muzzle Brake
Measure the diameter of your gun's barrel. Be sure to measure the distance from outer wall to outer wall (not just the diameter of the barrel opening). This measurement will determine the appropriate size of the muzzle brake.
Purchase a 6-inch-long cylindrical steel tube from an industrial supply company or a hardware store. The tube should have the same diameter (from outer wall to outer wall) as the barrel of your gun. The walls of the tube should be approximately 1 inch thick.
Use a metal boring machine to enlarge the radius of part of the cylindrical steel tube. Insert the metal tube into the boring machine, and thin the outer walls of the tube to ½ inch. Do this for the first 3 inches of the cylindrical steel tube.
Use the metal boring machine to taper the 4th inch of the steel tube. Move the steel tube back and forth along the boring machine to create a smooth taper. This taper will center the muzzle brake on the barrel and will prevent the muzzle brake from sliding off.
Saw 6 linear cuts into the top and bottom of the muzzle brake. The cuts should be approximately 1/3 of an inch thick and 1/3 of an inch apart. Make sure that the cuts go all the way through and create long holes in the top and bottom of the muzzle brake.
Drill a ¼ inch hole into the bottom of the tapered end of the muzzle brake. This hole will allow you to fasten the muzzle brake to the gun's barrel with a flat-end screw. Drill a ¼ inch hole into the bottom of the tapered end of the muzzle brake. This hole will allow you to fasten the muzzle brake to the gun's barrel with a screw.