Runout correction rifle barrel

• US 6,739,083 B2
• Filed: 09/12/2001
• Issued: 05/25/2004
• Est. Priority Date: 09/12/2001
• Status: Expired due to Fees

• Current Assignee: BORE Science Technologies LLC
• Original Assignee: BORE Science Technologies LLC
• Inventors: Martin, James
• Primary Examiner(s): Carone, Michael J.
• Assistant Examiner(s): Buckley, Denise J
• Application Number:
  US09/952,879
• Publication Number:
  US 20040035043A1
• Time in Patent Office: 986 Days
• Field of Search: 42/77, 42/78, 42/79, 42/750.1, 42/761, 42/760.1, 89/140.5, 89/147, 102/444, 102/439
• US Class Current: 42/78
• CPC Class Codes: F41A 21/16 Barrels or gun tubes characterised by the shape of the bore
• CPC Class Codes: F41A 21/18 Grooves-Rifling
• CPC Class Codes: F41A 21/28 Gas-expansion chambers; Barrels provided with gas-relieving ports F41A1/06, F41A13/08 and F41A21/36 take precedence

Abstract

A rifle barrel for realigning a projectile which is propelled through the barrel by gas pressure, the barrel comprising: a bore having a bore diameter through which a projectile may travel; rifling ridges within the bore; and at least one bore expansion chamber in the bore, wherein a diameter of the at least one bore expansion chamber is greater than the bore diameter, wherein a length of the at least one expansion chamber is smaller than an overall length of the projectile and greater than a contact length of the projectile. A process for projecting a projectile from a rifle barrel, the process comprising: increasing gas pressure behind the projectile in the rifle barrel, whereby the projectile is propelled through the rifle barrel; and passing a burst of gas around the projectile, whereby the projectile is aligned coaxially in the rifle barrel.

Claims

1. A rifle barrel for realigning a projectile which is propelled through the barrel by gas pressure, said barrel comprising:

a bore having a bore diameter and a bore length through which a projectile may travel which has an overall projectile length which is less than the bore length and a contact length that is less than the overall projectile length; and

rifling ridges within said bore to contact a projectile along the contact length and rotate the projectile within the bore;

at least one bore expansion chamber within said bore, wherein a diameter of at least one bore expansion chamber is greater than the bore diameter, wherein the at least one bore expansion chamber has a length that is smaller than the bore length, smaller than the overall projectile length, and greater than the contact length of the projectile, and

wherein the bore expansion chamber is free of the rifling ridges.

2. The rifle barrel of claim 1, wherein said at least one bore expansion chamber comprises a plurality of bore expansion chambers in said bore.

3. The rifle barrel of claim 1, wherein the at least one bore expansion chamber is more than three projectile lengths from a muzzle of said barrel.

4. The rifle barrel of claim 1, wherein the length of said bore expansion chamber is between about 101% and 110% of the contact length of the projectile.

5. The rifle barrel of claim 1, wherein a maximum diameter of said at least one bore expansion chamber is between about 101% and about 115% of the bore diameter.

6. The rifle barrel of claim 1, wherein said at least one bore expansion chamber comprises a smoothly transitioning surface from a start to an end of said at least one bore expansion chamber.

7. The rifle barrel of claim 1, wherein more than one of the chamber diameters of said at least one bore expansion chamber are greater than the bore diameter.

8. The rifle barrel of claim 1, wherein all of the chamber diameters of said at least one bore expansion chamber are greater than the bore diameter.

9. A rifle for improved runout correction of a bullet fired by the rifle, the rifle comprising a rifle barrel having a muzzle and a breech, the rifle barrel comprising:

a bore having a bore diameter and through which a projectile may travel from breech to muzzle;

a bore expansion chamber in said bore to align a bullet traveling down the bore, the bore expansion chamber having a diameter that is greater than the bore diameter; and

a plurality of radially inwardly projecting rifling ridges disposed in a spiral pattern along the bore, the spiral pattern of the rifling ridges being free of the bore expansion chamber.

10. The rifle of claim 9 wherein there are a plurality of bore expansion chambers along the bore.

11. The rifle of claim 9 wherein the bore provides a circular circumference and the bore expansion chamber has a larger diameter upon substantially the entire circular circumference of the bore.

12. The rifle of claim 9 wherein the distance from the muzzle to the bore expansion chamber is not less than six inches.

13. The rifle of claim 9 wherein the distance from the breech to the bore expansion chamber is not less than six inches.

14. The rifle of claim 9 wherein the diameter of the bore expansion chamber is between about 101% and about 115% of the bore diameter.

15. The rifle of claim 9 wherein the bore expansion chamber comprises a smoothly transitioning surface from a start to an end of the bore expansion chamber.

16. A rifle and projectile combination comprising:

a rifle having a rifle barrel comprising;

a bore extending from a muzzle to a breech, the bore having a bore diameter and through which a projectile may travel from breech to muzzle;

a bore expansion chamber in said bore to align a bullet traveling down the bore, the bore expansion chamber having a diameter that is greater than the bore diameter;

a plurality of radially inwardly projecting rifling ridges disposed in a spiral pattern along the bore, the spiral pattern of the rifling ridges being free of the bore expansion chamber

a projectile for traveling along the bore of the rifle, the projectile having a projectile length and a contact patch that contacts the rifling ridges and the bore as the projectile travels along the bore, the contact patch having a contact length.

17. The rifle and projectile combination of claim 16 wherein the bore expansion chamber has a length that is smaller than the projectile length and greater than the contact length.

18. The rifle and projectile combination of claim 16 wherein the length of the bore expansion chamber is between 101% and 115% of the contact length.

19. The rifle and projectile combination of claim 16 wherein the bore expansion chamber is more than three projectile lengths from the breech and more than six inches from the muzzle.

20. The rifle and projectile combination of claim 16 wherein the projectile has a caliber and the bore expansion chamber has a chamber depth that is related to the caliber by the following equation: