Extreme duty machine gun barrel
OwnerJohn Noveskeinventor
Life of this patent
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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.
Claims22
A process for manufacturing a gun barrel comprising the steps of:
- obtaining a bar of tool steel having a longitudinal axis, a front, a rear, and an exterior surface;
- hardening the bar of steel to a specified hardness;
- cutting the bar of steel to a specified length;
- drilling a hole through the bar of steel that is registered with the longitudinal axis of the bar of steel;
- reaming a bore through the bar of steel that is registered with the longitudinal axis of the bar of steel, thereby defining an interior surface of the bar of tool steel encompassing the bore;
- reaming a chamber in the rear of the bar of steel;
- preheating the bar of steel;
- heating the bar of steel to change the crystal structure of the bar of steel from ferrite to austenite;
- nitriding the bar of steel to create an oxide layer on both the exterior and interior surfaces of the bar of steel and a diffusion layer beneath each of the oxide layers;
- cooling the bar of steel;
- rinsing the bar of steel;
- and
- cleaning the bar of steel;
- and
- wherein a core of the bar of steel located between the diffusion layers has been hardened to a hardness of at least 50 HRC and not greater than 55 HRC.
Dependencies are inferred from the claim text.