Firearm magazine cartridge converter

#The technical field of this invention relates to firearms and more particularly to an improvement in a means for adapting a different caliber sized magazine cartridge for firing in a firearm.

#______________________________________ 1,407,633 F. F. Burton 2,396,816 J. L. Boudreau 2,507,364 C. H. Benson 3,110,122 D. D. Musgrave 3,776,095 Atchisson 4,069,608 Jurek 4,079,535 Elbe et al. 4,139,958 Foote 4,586,281 Chesnut 5,153,359 Lishness 5,566,488 Yap 5,761,841 Snick ______________________________________

#The present invention relates to an improvement in a conversion kit for allowing a 5.56 mm NATO or 7.62.times.39 AR-15 or M-16 rifle to fire a 9 mm parabellum equivalent. Conversion kits for converting a M16 rifle for firing a 9 mm round are known. Such kits include a barrel replacement assembly which quite readily can be replaced for the standard M-16 round. However, the conversion of such a M-16 rifle further must include a more evasive change in the structure of the magazine receiver.

#FIG. 1 is a side elevation view of a rifle of the type in which the invention is used.

#FIG. 2 is a partial fragmentary vertical sectional view through the rifle of FIG. 1

#FIG. 3 is a perspective view showing the prior art conversion kit in solid line and the receiver frame in phantom line.

#FIGS. 1 and 2 illustrate an automatic firearm 20 of the gas operated type. The firearm 20 depicted is of a known design and may be, for example, an M16 rifle commonly used by the United States military personnel. It comprises a receiver assembly 22, having an upper chamber 24 for receiving a bolt assembly 26. The receiver includes a receiver extension which is rigidly connected with a stock 30. Operatively connected forwardly of the chamber 24 is a barrel 32 having a firing chamber 34 in which is positioned a cartridge 36. A hand grip 38 is mounted on the barrel for isolating the user from direct contact with the barrel.

#A trigger mechanism 41 is provided and is generally similar to that which is discussed in U.S. Pat. No. 3,236,155. Generally speaking, it should be seen that upon pulling of a trigger 42, a spring biased hammer 44 is released after a trigger sear 45 is dislodged from a disconnect surface 43 on the hammer. This enables the hammer to rotate clockwise through a slot in a bolt carrier 48 to strike firing pin 50 to fire the cartridge 36. Thereupon, a portion of the expanded gases developed on firing of the firearm passes through a gas port in the barrel at the front of the site, through the gas tube 47 and through a gas passable 54 on the bolt carrier to actuate the automatic recoil of the cartridge shell and subsequent successive chambering of cartridges 36 and in the cartridge magazine 40 as the bolt carrier returns to the battery position after recoil.

#As illustrated in FIGS. 2 and 5, the receiver assembly 22 is defined by a receiver frame 60 defining a receiver chamber 62 for receiving the magazine cartridge 40 therein. As illustrated, the upper receiver frame 60 further includes a transverse bore 61 into which is received a cylindrical portion 65 of a magazine catch 66. The magazine catch further includes an inwardly directing end 68 which is correspondingly sized and shaped to be received within a corresponding catch opening 70 formed through the side wall 63 of the receiver 60. The catch is normally biased to a closed position, i.e. drawn up against the outer surface of the side wall 63 of the receiver 60 through the intermediary of an expansion spring 72 coaxially disposed about the free end 67 of the cylindrical portion 65 of the catch 66. A button 74 is fixably secured to the free end 67 of the catch 66 and captures the expansion spring 72 between it and the opposite side wall 71 of the receiver frame 60.