Barrel extension for firearm

Patent metadata

Field	Value
Publication number	US-9464859-B2
Application number	US-201514816306-A
Country	US
Kind code	B2
Filing date	Aug 3, 2015
Priority date	Aug 1, 2014
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

A firearm with barrel extension comprises a receiver, a barrel supported by the receiver that defines an ammunition shell chamber, and a rotatable locking bolt having radial bolt lugs. The bolt is carried by a slide disposed in the receiver for forward and rearward movement. A barrel extension is mounted on a rear end of the barrel which includes radial bolt locking lugs that rotatably engage the bolt lugs when the bolt is in a closed locked breech position in battery with the head of a chambered shell. The barrel extension includes a rear facing annular rim seating surface formed integrally on the barrel extension as a unitary structural part thereof. The rim seating surface extends radially inwards from an interior surface of the barrel extension to engage and support the rear rim of the chambered shell. The headspacing is defined entirely by the barrel extension independently of the barrel.

First claim

What is claimed is:

1. A firearm with barrel extension comprising:
a longitudinal axis;
a receiver;
a barrel supported by the receiver and including a front muzzle end, a rear breech end defining a chamber for holding an ammunition shell, and an axial bore extending between the ends;
a bolt supported by the receiver for axial forward and rearward movement, the bolt comprising a bolt head including a plurality of bolt lugs extending radially outward from the bolt and rotatable between locked and unlocked breech positions;
a tubular barrel extension having a front end coupled to the rear breech end of the barrel and a rear end defining a plurality of bolt locking lugs that rotatably engage the bolt lugs when the bolt is in the locked breech position; and
a rear facing annular rim seating surface formed integrally on the barrel extension as a unitary structural part thereof, the rim seating surface extending radially inwards from an interior surface of the barrel extension and arranged to engage a rim of a shell when positioned in the chamber;
wherein the rim seating surface is disposed inside an axial cavity formed in the barrel extension between the front and rear ends;
wherein the barrel extension includes an inwardly radially extending annular protrusion in the axial cavity of the barrel extension that defines the rear facing annular rim seating surface on a first side of the annular protrusion and a front facing annular mounting surface on a second side of the annular protrusion that engages a mating rear facing annular surface formed on the breach end of the barrel; and
wherein the rim seating surface of the barrel extension is circumferentially continuous except for an axially extending extractor slot formed in the seating surface that receives a hooked front end of an extractor that engages the rim of the shell for extracting the shell from the chamber.

2. The firearm according to claim 1 , wherein the barrel extension is detachably mounted on the rear breech end of the barrel.

3. The firearm according to claim 1 , wherein the front end of the barrel extension includes an internally threaded portion that rotatably engages an externally threaded portion of the barrel.

4. The firearm according to claim 1 , wherein the rim seating surface is obliquely angled to longitudinal axis.

5. The firearm according to claim 4 , wherein the mounting surface on the annular protrusion and the rear facing annular surface on the breach end of the barrel are each obliquely angled with respect to the longitudinal axis and configured to form a flat-to-flat surface engagement when the barrel extension is mounted on the barrel.

6. The firearm according to claim 1 , wherein the rear facing annular surface on the breach end of the barrel is circumferentially continuous and uninterrupted for a full 360 degree extent.

7. The firearm according to claim 1 , wherein the extractor slot further penetrates the rear end of the barrel extension.

8. The firearm according to claim 1 , wherein an axial distance between the rim seating surface and a front breach surface of the bolt head define a headspace.

9. The firearm according to claim 1 , further comprising a circumferential groove disposed inside the barrel extension between the annular rim seating surface and the barrel locking lugs that receives the bolt lugs, the bolt lugs being rotatable within the groove for rotating the bolt between the unlocked and locked breech positions.

10. The firearm according to claim 1 , wherein the rim of the shell when positioned in the chamber engages the annular rim seating surface but not an annular rear-facing surface of the breech end of the barrel.

11. A firearm with barrel extension comprising:
a receiver;
a barrel supported by the receiver and including a front muzzle end, a rear breech end defining a chamber configured to hold an ammunition shell, and an axial bore extending between the ends that defines a longitudinal axis;
a slide movably disposed in the receiver for axial forward and rearward movement;
a bolt supported by the slide and axially movable forward and rearward with the slide, the bolt comprising a bolt head including a plurality of bolt lugs extending radially outward from the bolt and rotatable between locked and unlocked breech positions;
a tubular barrel extension having a front mounting portion coupled to the rear breech end of the barrel and a rear locking portion defining a plurality of bolt locking lugs that rotatably engage the bolt lugs when the bolt is in the locked breech position; and
a rear facing annular rim seating surface formed integrally on the barrel extension as a unitary structural part thereof, the rim seating surface disposed inside an axial cavity formed in the barrel extension between the front and rear portions, and extending radially inwards from an interior surface of the barrel extension;
wherein the barrel extension includes an inwardly radially extending annular protrusion in the axial cavity of the barrel extension that defines the rear facing annular rim seating surface on a first side of the annular protrusion and a front facing annular mounting surface on a second side of the annular protrusion that engages a mating rear facing annular surface formed on the breach end of the barrel;
wherein the rim seating surface of the barrel extension is circumferentially continuous except for an axially extending extractor slot formed in the seating surface that receives a hooked front end of an extractor that engages the rim of the shell for extracting the shell from the chamber;
wherein when a shell having a case and a rear rim is loaded in the chamber in a forward-most position, the case engages the chamber in the barrel and rim engages the rim seating surface of the barrel extension.

12. The firearm according to claim 11 , wherein the rim seating surface is obliquely angled to longitudinal axis.

13. The firearm according to claim 12 , wherein the mounting surface is obliquely angled to the longitudinal axis.

14. A barrel extension for a firearm with lockable breech, the barrel extension comprising:
a tubular body including an axial centerline, a front mounting portion configured for coupling to a rear breech end of a firearm barrel, and a rear locking portion, the barrel extension including circumferential sidewalls extending longitudinally between the mounting and locking portions that defines an internal axial cavity;
a plurality of inwardly extending radial bolt locking lugs in the rear locking portion;
a plurality of axial channels disposed between the bolt locking lugs which extend forward from a rear end of the barrel extension into a circumferential groove located in front of the bolt locking lugs, wherein the bolt locking lugs are configured to rotatably engage radial bolt lugs of a lockable bolt of the firearm when the bolt lugs positioned in the circumferential groove and rotated; and
a rear facing annular rim seating surface formed integrally on the barrel extension as a unitary structural part thereof and between the front and rear portions, the rim seating surface extending radially inwards from the sidewalls in the axial cavity and positioned to engage a radially protruding rim of an ammunition shell when inserted into the barrel extension from the rear end;
wherein the barrel extension includes an inwardly radially extending annular protrusion in the axial cavity of the barrel extension that defines the rear facing annular rim seating surface on a first side of the annular protrusion and a front facing annular mounting surface on a second side of the annular protrusion that engages a mating rear facing an

Assignees

• Sturm Ruger & Co

Inventors

• Potter Dwight
• Hawkins Benjamin Gerard
• Tilton Michael Robert

Classifications

• F41A21/482

  using continuous threads on the barrel · CPC title

• F41A21/485 Primary

  using screws or bolts · CPC title

• F41A21/12

  Cartridge chambers; Chamber liners (F41A3/74, F41A9/46, F41A21/04 take precedence) · CPC title

• F41A3/30

  Interlocking means, e.g. locking lugs, screw threads · CPC title