# US 2014/0150320 A1 · Gun barrel rifling

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- Number: US 2014/0150320 A1
- Document ID: US20140150320A1
- Status: Published application
- Kind: A1
- Application number: 13/694,264
- Filed: 2012-11-14
- Published: 2014-06-05
- Earliest claimed: 2011-11-15
- Assignees: F. J. Feddersen, Inc.
- Inventors: Frederick J. Feddersen
- Web page: https://patentgrep.com/patent/US20140150320A1

## CPC

- F41A 21/18: Grooves-Rifling
- F41A: FUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE

## 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.

## Claims

### Claim 1

A gun barrel having a combination of standard rifling and polygonal rifling comprising helically disposed rifling grooves in a barrel bore and having a single edge area and a flat area between said grooves and said bore.

### Claim 2 (depends on 1)

A gun barrel according to claim 1 wherein there are six grooves and five bore areas.

### Claim 3 (depends on 2)

A gun barrel according to claim 2 further comprising a flat area adjacent said single edge area.

### Claim 4 (depends on 1)

A gun barrel according to claim 1 wherein said flat area transitions gradually from said grooves to said bore.

### Claim 5 (depends on 4)

A gun barrel according to claim 4 wherein the length of said flat area is in the range of about 0.005 to about 0.010 inches.

### Claim 6 (depends on 3)

A gun barrel according to claim 3 wherein the dimensions of said gun barrel comprise
GD1A=0.222 inches
BD1A=0.217 inches
FD1A=0.212 inches
FL2A=0.010 inches
FL3A=0.005 inches
BL4A=0.053 inches
GL5A=0.061 inches.

### Claim 7 (depends on 2)

A gun barrel according to claim 2 further comprising a non-flat area adjacent said single edge area.

### Claim 8 (depends on 7)

A gun barrel according to claim 7 wherein the dimensions of said gun barrel comprise
GD1B=0.222 inches
BD2B=0.219 inches
FD1B=0.212 inches
FL2B=0.007 inches
BL4B=0.056 inches
GL5B=0.058 inches.

### Claim 9 (depends on 1)

A gun barrel according to claim 1 wherein the rifling provides a twist in the rifled barrel which is substantially uniform from the breech end of the barrel to the muzzle end of the barrel.

### Claim 10 (depends on 1)

A gun barrel according to claim 1 wherein a bullet fired through the barrel will not have any substantial deformation due to the single edge area and the flat area between the bore and grooves.

### Claim 11 (depends on 1)

A gun barrel according to claim 1 wherein a bullet fired through the barrel follows the helix angle of the rifling and the stress from the wind up effect of the bullet creates substantially no or little bullet deformation.