Donald R Barker

US Patent:

57653038, Jun 16, 1998

Filed:

Sep 30, 1996

Appl. No.:

8/723361

Inventors:

Henry A. Rudkin - Sant Julia, AD
Donald Barker - Cody WY

International Classification:

F41A 2100

US Classification:

42 78

Abstract:

Rifling for the barrel of a firearm includes a first gain twist region for increasing the rotational velocity of a bullet as it travels from the breech towards the muzzle end of the barrel, and a second region in which the rifling is of a constant twist so that the bullet exits the muzzle end of the barrel at a constant rotational velocity. The bore defined in the barrel is tapered in a direction from the breech end to the muzzle end so that the diameter of the muzzle opening of the barrel is less than the diameter of the breech opening. The angle of the rifling is variable with the rate of the gain twist of the rifling. The gain twist of the rifling in the barrel is formed by a button, preferably having a sinusoidal shaped periphery, which is pulled through the barrel during the manufacturing process. The smooth periphery of the button prevents shredding of the barrel when the button is twisted at different speeds to provide the variable gain twist of the rifling in different sections of the barrel. In a further aspect of the invention, an apparatus is provided for selectively varying the rotational speed of the button to form the desired gain twist of the rifling during manufacture of the barrel.

US Patent:

58947701, Apr 20, 1999

Filed:

May 9, 1997

Appl. No.:

8/853802

Inventors:

Henry A. Rudkin - Sant Julia, AD
Donald Barker - Cody WY

International Classification:

B23B 100

US Classification:

82 111

Abstract:

Rifling for the barrel of a firearm includes a first gain twist region for increasing the rotational velocity of a bullet as it travels from the breech towards the muzzle end of the barrel, and a second region in which the rifling is of a constant twist so that the bullet exits the muzzle end of the barrel at a constant rotational velocity. The bore defined in the barrel is tapered in a direction from the breech end to the muzzle end so that the diameter of the muzzle opening of the barrel is less than the diameter of the breech opening. The angle of the rifling is variable with the rate of the gain twist of the rifling. The gain twist of the rifling in the barrel is formed by a button, preferably having a sinusoidal shaped periphery, which is pulled through the barrel during the manufacturing process. The smooth periphery of the button prevents shredding of the barrel when the button is twisted at different speeds to provide the variable gain twist of the rifling in different sections of the barrel. In a further aspect of the invention, an apparatus is provided for selectively varying the rotational speed of the button to form the desired gain twist of the rifling during manufacture of the barrel.