GB2446007A - Cartridge magazine for firearms having a prismatic cavity - Google Patents

Abstract

A magazine 1 for cylindro-conical cartridges for firearms is disclosed wherein the internal form 2,3 of the magazine constrains the projectile ends 9 of cartridges 6,7 into a single column (along axis 10,Figure 4), yet compels the bases of alternate cartridges 6,7, when placed under load, to form two columns (along axes 11,12,Figure 5). The purpose of this arrangement being to negate the cartridge taper in one plane permitting a straight column magazine combining properties of conventional single and double column magazines.

Description

1 2446007 A cartridge magazine for firearms The present invention

relates to a cartridge magazine for firearms Cartridge magazines for firearms are well known in the art.They serve to store cartridges and feed cartridges into the mechanism of firearms Typically such magazines store cartridges stacked either in a single column or in two interacting columns. All cartridges sre of essentially cylindro-conical form with a projectile at the minor diameter, the major diameter being the base of the cartridge Cartridges may be divided into two classes, those wherein the base of the cartridge is of larger diameter than the cartridge body forming a rim at the base and those cartridges having a circumferential groove at the base known as rimless cartridges The purpose of the rim or groove being to facilitate mechanical handling by the firearm mechanism A disadvantage of the single column magazine is that adjacent cartridges are in line contact along the major axis of each cartridge The effect of the taper on each cartridge is therefore accumulative along the column requiring a curved magazine that is difficult to manufacture and wasteful of space for storage and transport A disadvantage of double column magazines is that the taper on each cartridge acts on adjacent cartridges in two planes, this limits the magazine to cartridges that have a taper of less than 2 degrees per side, an increase of angle of taper much above 2 degrees per side causes loss of control when feeding from the magazine into the mechanism of a firearm According to the present invention there is provided a magazine for cartridges for firearms provided with an internal cavity of prismatic form to accept and store said cartridges, the cartridges being of cylindro-conical form with a projectile at the minor diameter end of the cartridge the form of the prism being that of a cartridge bisected along the major axis, with the two halves cojoined at the centre of the minor diameter and with the two halves seperated at the base such that the bisection line on each half forms one of the two equal sides of an isosceles triangle with the projectile at the apex, the prism walls thus mirror the form of a cartridge of increased taper, such that any cartridges placed in the cavity will, under influence of gravity or applied load, stack with the projectile ends forming a single column of a length equal to the sum of projectile diameters at the point adjacent projectiles contact, yet the bases of alternate cartridges will form two columns thus negating the difference between major and minor diameters in one plane causing the cartridges to align in a straight column under the influence of the prismatic form of the magazine Advantageously the magazine form proposed, by forcing cartridges into a straight column, eases manufacture, transport and storage even with cartr -idges of significant taper A further advantage is that unlike a double column magazine where the cartridges must move sideways in feeding to assume the presentation of a single column magazine, the proposed magazine form by aligning the projectiles in a single column the has feeding characteristics similar to a single column magazine combined with an enhanced cartridge taper negating character over and above those of a double column magazine The present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1:-Is a schematic cross section of the magazine showing the prismatic form of the internal cavity Figure 2:-Is a schematic cross section of the magazine body showing two cartridges in the prismatic cavity Figure 3 Is a schematic cross section of the magazine in side elevation showing three cartridges therein Figure 4 Is a schematic cross section in end elevation from the projectile end Figure 5:-Is a schematic cross section in end elevation from the base end of the cartridge A magazine body (1) has a cavity (4) to receive cartridges (6 and 7) The walls (2 and 3) of the cavity (4) mirror the profile of a cartridge but are divergent from the projectile (9) end at an angle greater than the taper of the cartridge (6 or 7) The cavity (4) being wider at the end that receives the base of cartridges (6 and 7) than the base of each cartridge (6 or 7) , and the cartridges being of cylindro-conjcal form any load applied along the axes (10,11 and 12) will cause alternate cartridges (6 or 7) to bear against alternate walls (2 or 3) thus the bases of cartridges (6 or 7) will form into two columns on axes (ii and 12) ,yet the column of projectiles is Constrained to a sinle column on axis (10). By imposing this formation on cartridges stacked therein the magazine aligns cartridges (6 and 7) such that the major axes (8) are parallel when viewed in the plane shown in figure 3. Thus a straight magazine form is possible even with cartridges of significant body taper. If the cartridges are of the rimmed form,as with (6 and 7) , a groove (5) may be provided to accomodate that portion of the rim that bears alternately against wafls (2 or 3) , to help prevent rims slipping over each other causing misalignment of the column of cartridges, to this end the major axis of the cavity as shown in figure 1 is closely matched to the length of cartridges (6 and 7).

Claims (1)

1. CLAIM

   1 -A magazine for cartridges for firearms provided with an internal cavity of prismatic form to accept and store said cartridges, the cartridges being of cylindro-conical form provided with a projectile at the minor diameter end of the cartridge, the form of the prism being that of a cartridge bisected along the major axis with the two halves cojoined at the centre of the minor diameterand with the two halves seperated at the base such that the bisection line on each half forms one of the two equal sides of an isosceles triangle with the projectile at the apex, such that any cartridges placed in the cavity will, under the influence of gravity or applied load, stack with the projectile ends forming a single column of a length equal to the sum of projectile diameters at the point adjacent projectiles contact, yet the bases of alternate cartridges will form two columns thus negating the difference between major and minor diameters in one plane causing the cartridges to align in a straight column under the influence of the prismatic form of the magazine