Abstract: A muzzle brake and tool for effectively installing the brake on the muzzle end of a rifle without the necessity of engaging the services of a gunsmith. The tool for installation includes a handle assembly, a bore pilot and an insertable threading die and cutter and cutter holder by which the owner of the rifle can effectively trim the end of the barrel and then form threads on the external surface of the barrel onto which the muzzle brake can be screw threaded. The muzzle brake is a hollow cylindrical member having an internally threaded end engaged with the externally threaded end of the muzzle of the rifle together with two flat sides and four vents extending horizontally when installed on the rifle barrel with the vents being equally spaced and equally sized and communicating the hollow interior of the muzzle brake with the atmosphere to release gases thereby reducing recoil felt when the gun is fired.