Abstract: Disclosed herein is a method of manufacturing two or more gun barrels, the method comprising: machining (103) a single metal block to form a barrel preform having the outer shape of at least a first gun barrel and a second gun barrel; drilling (105) a first hole through the first gun barrel to form a first barrel bore; and drilling (107) a second hole through the second gun barrel to form a second barrel bore. Advantages include the barrels being integrally attached to each other and so a soldering operation to attach the barrels to each other is avoided.

Abstract: A barrel assembly for firearms including one or more tubes associated with a mono-block, characterized in that the mono-block has one or more cylindrical protrusions which allow the connection of one or more of the tubes and the subsequent joining thereof by welding, adhesive bonding, forcing, etcetera. The method for manufacturing the barrel assembly is characterized in that it includes the steps of: providing a mono-block which includes one or more front cylindrical protrusions, one or more partial chambers axially aligned with the protrusions, and corresponding collars for the cartridge seats, extractor seats, and closure members such as closure tenons or other members; all the members are completed with their final dimensions; performing an overall heat treatment of the mono-block and of the barrels; connecting the tubes, which constitute the barrels of the firearm, by welding, adhesive bonding, forcing, etcetera, to the protrusions.

Abstract: A unitary barrel, chamber and action assembly for a firearm is manufactured from a single piece of metal stock so as to precisely and consistently meet headspace requirements. A single piece of metal stock having a bore centerline is successively reamed based on a common datum to achieve precise headspace compliance. The unitary assembly is then profiled, again based on measurements from the datum, to provide a unitary barrel, chamber and action assembly without any form of juncture, headspace or harmonic limitations.

Abstract: An extreme duty machine gun barrel has body having a central bore. The rear opening of the body includes a chamber formed to receive a cartridge. The body has a surface layer covering all surfaces of the body. The body has a diffusion layer extending below the surface layer into an underlying material of the body. The central bore may have rifling defined by lands and grooves formed in the bore. An interior portion of the body may have a hardness of at least 50 HRC and not greater than 55 HRC after the surface layer and diffusion layer are created on the body. The surface layer and diffusion layer may be created by subjecting the body to a ferritic nitrocarburizing treatment followed by an oxy nitrocarburizing treatment. The nitrocarburizing treatments may be repeated. The body may be AISI H13 grade tool steel.

Abstract: A method for manufacturing double barrel shotgun barrels, including the steps of providing an elongated metal stock material having a first end and a second end, forming two index holes in both the first end and the second end of the material, forming a first and second bore hole through the material, and then profiling the material into a desired gun barrel profile. 16. Double barrel shotgun barrels formed from a single piece of elongated solid metal stock material according to the process of the invention are also taught.