Abstract: A method of making a gun barrel having a breech end and a muzzle end and a bore extending between the two ends comprises applying to the outer surface of the bore a plurality of swaging dies (5), each of which carries an upstanding helical land (10). The dies are pressed simultaneously against the external surface of the gun barrel such that each land forms a helical recess (14) in the external surface and crystalline deformation to the material of the barrel wall immediately below the external helical recess. The distortion of the external surface results simultaneously in the creation of a plurality of smooth helical ridges (16) on the surface of the bore.

Abstract: A method of making a gun barrel having a breech end and a muzzle end and a bore extending between the two ends comprises applying to the outer surface of the bore a plurality of swaging dies (5), each of which carries an upstanding helical land (10). The dies are pressed simultaneously against the external surface of the gun barrel such that each land forms a helical recess (14) in the external surface and crystalline deformation to the material of the barrel wall immediately below the external helical recess. The distortion of the external surface results simultaneously in the creation of a plurality of smooth helical ridges (16) on the surface of the bore.

Abstract: The present invention relates to a constant velocity universal joint comprising two shafts (1, 2) each having a claw (3, 4) located on one end. First and second hinge elements (5, 6) are rotatably mounted between the claws (3, 4). A cage (7, 8) is also provided which can reciprocate with respect to the hinge elements (5, 6) in the direction of the hinge axis (H).