US3711981A

US3711981A - Cartridge magazine

Info

Publication number: US3711981A
Application number: US00084957A
Authority: US
Inventors: L Seecamp
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-10-29
Filing date: 1970-10-29
Publication date: 1973-01-23
Anticipated expiration: 1990-01-23

Abstract

A box-magazine for cartridges in which the side walls are provided with integral knock-out fingers which have inwardly bent projections at their free ends for engagement within the extractor grooves of the cartridges, thereby preventing the cartridges from being thrown forward in the magazine against the front wall.

Description

United States Patent [1 1 Seecamp [451 Jan. 23, 1973 1 CARTRIDGE MAGAZINE [76] inventor: Louis W. Seecamp, 561 Whitney Avenue, New Haven, Conn.

[22] Filed: Oct. 29, 1970 [2i] Appl. No.: 84,957

[52] U.S. Cl ..42/50 [51] Int. Cl ..F4lc 25/02 [58] Field of Search ..42/50 [56] References Cited UNITED STATES PATENTS YZITR J EIIiot" ..142/50 Mannlicher ..42/50 Into ..42/50 Primary Examiner-Benjamin A. lBorchelt Assistant Examiner-C. T. Jordan [57] ABSTRACT A box-magazine for cartridges in which the side walls are provided with integral knock-out fingers which have inwardly bent projections at their free ends for engagement within the extractor grooves of the cartridges, thereby preventing the cartridges from being thrown forward in the magazine against the front wall.

7 Claims, 4 Drawing Figures PAIENTEU JAN 23 I975 INVENTOR [00/5 M1 seecm CARTRIDGE MAGAZINE The present invention relates to box-magazines for high-power firearms, and it relates more particularly to box-magazines in which the cartridges are protected against damage resulting from impact with the front wall of the magazine during recoil of the firearm.

Soft-nosed cartridges often are damaged by heavy recoil as they lie in the magazine. Heavy recoil usually propels a cartridge forward until it strikes the inner front wall of the magazine where damage is inflicted on the soft-nosed portion of the cartridge. Repeated battering of soft-nosed cartridges on the inner front wall of the magazine not infrequently causes a cartridge to become so deformed that it jams in the forearm when being chambered. Occasionally a cartridge becomes so mutilated that it may present a physical danger to the shooter. Even mild deformation of a soft-nosed cartridge, however, it not without its consequences for the shooter since deformation of the cartridge head adversely affects the accuracy of bullet flight.

The present invention virtually eliminates those annoying and often dangerous problems resulting from recoil damage to soft-nosed cartridges. In addition, the present invention does this in a way that is economically inexpensive from the manufacturing viewpoint. In

order to produce the device which prevents recoil damage to cartridge tips, the manufacturer need only use a simple blanking operation when fabricating the magazine from sheet metal.

The nature of the present invention is well illustrated by the box-magazine shown in the drawings; however, it should be noted that the invention can be used as part of other magazines not of the specific type which is here used to illustrate the principles of the invention. The box-magazine here shown is representative of the typical high-power firearm magazine and it can be used in conjunction with any standard high-power firearm.

Of the drawings:

FIG. 1 is a right-side perspective view of the magazine, the follower spring, cartridge follower and floor plate being removed and portions of the walls of the magazine being shown broken away for illustrative purposes.

FIG. 2 is a top view of the magazine as it would appear when loaded, portions again being broken away.

FIG. 3 is a transverse section of the loaded magazine taken on the line 33 of FIG. 2 and showing it attached to a firearm with the bolt in the normal position.

FIG. 4 is similar to FIG. 3, however the bolt section is not shown since the bolt is in the retracted position as it would be when preparing to engage a cartridge.

The drawings show a box-magazine which consists of a pair of parallel side walls 10, a pair of parallel end walls 11 (see FIGS. 1, 2), and a floor plate 12 (see FIGS. 3,4). The mechanism by which the magazine is attached to the receiver 13 is not shown since this may be any conventional latch means and has no bearing on the present invention. Each side wall is in part made up of a resilient arm or cartridge-retaining finger 14 (see FIG. 1) which terminates in an inward projection 15, the cartridge-retaining fingers 14 being of sufficient length to ensure enough resiliency so that the rims or flanges at the base of each cartridge 16 bend the fingers l4 outwardly when the cartridges 16 are forced to the back end of the magazine. The projections 15 are also tilted rearwardly, as shown in FIG. 2, in order to allow the cartridges 16 to slip easily backward so that the flanges rest behind the projections 15, while at the same time the rearward tilt serves to hold the cartridges l6 securely in that position once they have reached it. Each finger 14 is rigidly connected at one end to the adjacent side wall 10 and extends longitudinally of the cartridges 16 with the projection 15 at its free end near, but spaced from, the rear end wall of the magazine by a distance not substantially greater than the width of the rim or flange of each cartridge 16.

After loading the magazine in the customary way, the cartridges 16 can be rendered safe from recoil damage by striking the back outer surface 17 of the magazine against the hand or some other object. Inertia thus drives the cartridges 16 against the back inner wall of the magazine, where they are retained by the inward projections 15 found on the resilient arms 14. As shown in FIG. 2, the inward projections 15 on the resilient arms 14 engage the grooves 18 of the cartridges l6 and hold them against the back inner surface of the magazine. Consequently, the cartridge tips are protected from recoil damage.

The box-magazine shown in the drawings is longitudinally symmetrical with the exception of a follower 19 which is attached to the follower spring 20 (see FIGS. 3,4). The force exerted by the spring member 20 pushes the follower 19 upward. When the boxmagazine here illustrated is fully loaded, the asymmetrical shape of the follower 19 causes the cartridges 16 to be arranged in the configuration shown in FIGS. 3 and 4.

In FIG. 3 where the bolt 21 is in the normal forward position, the bottom longitudinal surface of the bolt 21 sets a limit on how far upward the follower spring 20 can push the cartridges 16. In FIG. 4 where the bolt 21 is in the retracted position and does not hold down the cartridges 16, a pair of feed lips 22 fulfills this function. The feed lips 22 are best shown :in FIG. 2. They also hold down the follower 19 when the magazine is empty. By comparing FIGS. 3 and 4 it can be seen that the bottom surface of the bolt 21 holds the cartridges 16 farther down in the magazine than the feed lips 22 do. As shown in FIG. 3, when the bolt 21 is in the forward or normal position, all cartridges 16 in the magazine have some portion of their grooves 18 engaged by some portion of the inward projections 115. Each cartridge 16 is then protected from recoil damage. When the bolt 21 is retracted, then the uppermost cartridge 16 moves to the position shown in FIG. 4. It then no longer is restrained by the inward projection 15 on the resilient arm 14. When the bolt 21 is brought forward, the uppermost cartridge 16 is carried forward with it and chambered as the bolt 21 reaches battery position.

In order to ensure that each cartridge 16 is restrained by one or the other of the retaining fingers 14, the upper end of each projection 15 is disposed from the adjacent feed lip 22 by a distance only sufficient to allow the cartridge 16 to be fed longitudinally out of the magazine when it is pressed against such feed lip 22.

What is claimed is:

1. A box-magazine for cartridges, each having a circumferential flange at its base forming an extractor shoulder, said box-magazine comprising a housing having opposite side walls, and front and rear end walls for the reception of a plurality of cartridges, feed lips 3 disposed on the upper edges of said side walls for retaining the cartridges and guiding them individually into the chamber of a firearm, a follower spring for urging the cartridges upwardly within said housing against said feed lips and at least one of said side walls having an elongated cartridge-retaining finger disposed longitudinally of the cartridges and having one end rigidly connected to said side wall and a free end spaced from said rear end wall by a distance not substantially greater than the thickness of the circumferential flange on each of the cartridges, the free end of said retaining finger having a projection directed inwardly of said side walls for engagement with the extractor shoulder of adjacent ones of said cartridges, the length of said retaining finger being sufficient to ensure adequate resiliency of said finger, thereby permitting the flanges of the cartridges to be forced rearwardly of said projection by resiliently bending said retaining finger outwardly while being rigid enough to prevent the flanges of the cartridges from moving forward of said projection during recoil of the firearm, the front end wall of said housing being spaced from the nose of each of the cartridges when their extractor shoulders are engaged by said projection.

2. A box-magazine as defined in claim 1, wherein each of said side walls is provided with a said elongated 4 cartridge-retaining finger.

3. A box-magazine as defined in claim 2, wherein said cartridge-retaining fingers are blanked out of the material forming said side walls.

4. A box-magazine as defined in claim 2, wherein the upper edge of each of said projections on said cartridge-retaining fingers is spaced from the said feed lip on the corresponding side wall a distance only sufficient to allow the cartridge being urged by said follower spring against the said feed lip to be fed longitudinally out of said magazine.

5. A box-magazine as defined in claim 4 for a firearm having a reciprocable branch both, wherein the cartridges are held out of engagement with said feed lips by a longitudinal surface of the bolt of the firearm when said magazine is assembled in a firearm in which thebolt is closed, such that all of the cartridges in said magazine are retained by said cartridge-retaining fingers against forward movement in said magazine.

6. A box-magazine as defined in claim I, wherein said cartridge-retaining finger is blanked out of the material forming said side wall.

7. A box-magazine as defined in claim 1, wherein said projection is slightly tilted toward the rear end wall of said housing.

Claims

1. A box-magazine for cartridges, each having a circumferential flange at its base forming an extractor shoulder, said boxmagazine comprising a housing having opposite side walls, and front and rear end walls for the reception of a plurality of cartridges, feed lips disposed on the upper edges of said side walls for retaining the cartridges and guiding them individually into the chamber of a firearm, a follower spring for urging the cartridges upwardly within said housing against said feed lips and at least one of said side walls having an elongated cartridge-retaining finger disposed longitudinally of the cartridges and having one end rigidly connected to said side wall and a free end spaced from said rear end wall by a distance not sUbstantially greater than the thickness of the circumferential flange on each of the cartridges, the free end of said retaining finger having a projection directed inwardly of said side walls for engagement with the extractor shoulder of adjacent ones of said cartridges, the length of said retaining finger being sufficient to ensure adequate resiliency of said finger, thereby permitting the flanges of the cartridges to be forced rearwardly of said projection by resiliently bending said retaining finger outwardly while being rigid enough to prevent the flanges of the cartridges from moving forward of said projection during recoil of the firearm, the front end wall of said housing being spaced from the nose of each of the cartridges when their extractor shoulders are engaged by said projection.

2. A box-magazine as defined in claim 1, wherein each of said side walls is provided with a said elongated cartridge-retaining finger.

5. A box-magazine as defined in claim 4, for a firearm having a reciprocable branch bolt, wherein the cartridges are held out of engagement with said feed lips by a longitudinal surface of the bolt of the firearm when said magazine is assembled in a firearm in which the bolt is closed, such that all of the cartridges in said magazine are retained by said cartridge-retaining fingers against forward movement in said magazine.

6. A box-magazine as defined in claim 1, wherein said cartridge-retaining finger is blanked out of the material forming said side wall.