Wear resistant ammunition feed ramp for light-weight firearms

Patent metadata

Field	Value
Publication number	US-2016341504-A1
Application number	US-201615155601-A
Country	US
Kind code	A1
Filing date	May 16, 2016
Priority date	May 20, 2015
Publication date	Nov 24, 2016
Grant date	—

Abstract

A light-weight firearm and related fabrication method are described for a wear resistant feed ramp for chambering cartridges from an ammunition magazine. In one embodiment, the firearm includes a barrel and a frame defining a magazine well and cartridge feed ramp. A wear insert formed of a different material than the frame is implanted in the feed ramp adjacent to the barrel chamber. The wear insert is then machined in situ to shape forming an obliquely angled wear surface. After machining, both the frame and implanted wear insert undergo a surface hardening process together. The surface hardened wear insert has a greater surface hardness than the surface hardened frame and is better adapted to resist wear after repeated chambering of rounds. In one non-limiting example, the frame may be hard anodized aluminum and the wear insert hard anodized titanium.

First claim

What is claimed is:

1 . A light-weight firearm with wear resistant cartridge feed ramp comprising:
a metallic frame defining a magazine well for insertably receiving an ammunition magazine; a barrel supported by the frame, the barrel including a longitudinally extending bore defining a longitudinal axis, a front muzzle end, and a rear breech end defining a rearwardly open chamber configured for holding a cartridge; an obliquely angled cartridge feed ramp formed by an integral unitary portion of the frame, the feed ramp disposed at an upper end of the magazine well near the rear breech end of the barrel and made of a same material as the frame; and a surface hardened wear insert affixed to the feed ramp adjacent to the chamber in the rear breech end of the barrel, the wear insert arranged to engage a cartridge being loaded into the chamber from the magazine; wherein the wear insert is formed of a different material than the feed ramp.

2 . The assembly according to claim 1 , wherein the wear insert includes an obliquely angled wear surface having a greater hardness than a surface of feed ramp of the frame.

3 . The firearm according to claim 2 , wherein the wear insert is formed of a material having a density greater than the frame but less than the density of steel.

4 . The firearm according to claim 3 , wherein the wear insert is made of hard anodized titanium and the frame including the feed ramp is made of hard anodized aluminum.

5 . The firearm according to claim 2 , wherein the wear insert has an elongated cylindrical body oriented vertically in the frame and the wear surface is formed on a rear face of the body adjoining the feed ramp of the frame.

6 . The firearm according to claim 5 , wherein the wear insert includes a top end positioned proximate to an annular rear entrance to the chamber and a bottom end including a downwardly extending mounting stem received in an upwardly open socket of the frame.

7 . The firearm according to claim 6 , wherein the frame includes a shoulder forming a horizontal surface on which the bottom end of the wear insert is abuttingly seated, the upwardly pen socket of the frame being formed in the horizontal surface.

8 . The firearm according to claim 6 , wherein the mounting stem and socket are threaded to rotatably couple the wear insert to the feed ramp.

9 . The firearm according to claim 5 , wherein the wear surface is arcuately concave in shape to conform to the shape of a front end of the cartridge.

10 . The firearm according to claim 1 , wherein the firearm is a pistol.

11 . The firearm according to claim 2 , wherein the wear surface has a compound angled configuration comprising an upper angled surface portion obliquely disposed at a first angle to a vertical centerline of the wear insert and a continuous adjoining lower angled surface portion obliquely disposed at a second angle to the vertical centerline, the first angle being different than the second angle.

12 . A light-weight frame with wear resistant cartridge feed assembly for a firearm, the frame comprising:
a longitudinal axis; a metallic body having an unitary monolithic structure formed of a first material and a hard anodized surface; a downwardly open magazine well configured for removably receiving an ammunition magazine; a breech area defined at a top of the magazine well; an obliquely angled cartridge feed ramp formed by an integral unitary portion of the frame proximate to the breech area, the feed ramp comprised of the same first material and hard anodized surface as the frame; and a machined wear insert affixed to the feed ramp, the wear insert including an obliquely angled hard anodized wear surface, the wear insert formed of a second material different than the first material of the frame; wherein the hard anodized wear surface of the wear insert has a greater hardness than the hard anodized surface of the frame.

13 . The frame according to claim 12 , wherein the wear insert is formed of a material having a density greater than the frame but less than the density of steel.

14 . The frame according to claim 13 , wherein the wear insert is made of hard anodized titanium and the frame including the feed ramp is made of hard anodized aluminum.

15 . The frame according to claim 12 , wherein the wear insert has an elongated cylindrical body oriented vertically in the frame and the obliquely angled wear surface is disposed on a rear facing side of the body adjoining the feed ramp of the frame.

16 . The frame according to claim 15 , wherein the wear insert includes a top end positioned proximate to an annular rear entrance to the chamber and a bottom end including a downwardly extending mounting stem received in an upwardly open socket of the frame.

17 . The frame according to claim 16 , wherein the frame includes a shoulder forming a horizontal surface on which the bottom end of the wear insert is abuttingly seated, the upwardly open socket of the frame being formed in the horizontal surface.

18 . A method for fabricating a firearm frame with hardened cartridge feed ramp, the method comprising:
providing a wear insert in a pre-machined shape; implanting the wear insert in a cartridge feed ramp portion of a firearm frame; machining the wear insert in situ to a post-machined shape different than the pre-machined shape; and surface hardening the wear insert and frame together simultaneously in a single surface hardening process step.

19 . The method according to claim 18 , wherein the surface hardening process step is performed by hard anodization.

20 . The method according to claim 18 , wherein the wear insert is made of hard anodized titanium and the frame is made of hard anodized aluminum.

21 . The method according to claim 18 , wherein the wear insert in the pre-machined shape comprises a vertically elongated full cylindrical body including a top end having a tool engagement feature and a bottom end having a mounting feature.

22 . The method according to claim 21 , wherein the implanting step includes vertically inserting the mounting feature in an upwardly open socket formed in the feed ramp portion of the frame.

23 . The method according to claim 22 , wherein the implanting step further includes threadably engaging threads of the mounting feature with mating threads of the socket.

24 . The method according to claim 23 , wherein the implanting step further includes engaging the tool engagement feature with a tool, and rotating the wear insert with the tool to threadably engage the mounting feature with the socket.

25 . The method according to claim 24 , wherein the tool engagement feature and the tool are hex shaped.

26 . The method according to claim 21 , wherein the wear insert in the post-machined shape comprises a part cylindrical body and an obliquely angled wear surface on a rear face of the wear insert.

27 . The method according to claim 21 , wherein the machining step completely removes the tool engagement feature.

28 . The method according to claim 18 , wherein the wear insert is formed of a material having a density greater than the frame but less than the density of steel.

Assignees

• Sturm Ruger & Co

Inventors

• Mochak Richard

Classifications

• F41A9/24 Primary

  using a movable magazine or clip as feeding element · CPC title

• F41A9/55 Primary

  Fixed {or movable} guiding means, mounted on, or near, the cartridge chamber · CPC title