Abstract: The present invention relates to rifling of a gun barrel to provide grooves and bores in the gun barrel separated by a single edge area and a polygonal area.

Abstract: The present invention relates to rifling of a gun barrel to provide grooves and bores in the gun barrel separated by a single edge area and a polygonal area.

Abstract: A gun drill guide is disclosed comprising a cylinder body member of a resilient polymer material having a central opening extending therethrough, a radially extending flange means at one end thereof to engage the end face of a bearing assembly and an annular groove near the opposite end thereof defined by second and third radially extending flanges for engaging the opposite end face of the bearing assembly. A locking member, a chip deflector assembly, a stabilizer assembly or other guide attachment are disclosed which may be attached to the drill guide.