The history of the development of firearms, especially as instruments of warfare and defense, has been guided by the goal of propelling the largest number of projectiles toward their target(s) as accurately and quickly as possible.  The number of cartridges that can be fired before stopping to reload is a critical factor in firearm efficiency, and firearm technology has thus progressed from the muzzle-loaded single-shot flintlock rifle to the "six-shooter" revolver, and on to the magazine-fed automatic and semi-automatic assault rifles of today.  The capacity of contemporary magazines for firearms is limited by factors of size, weight, handling, and overall dimensions.  A conventional stack-type magazine extends perpendicular to the barrel of the firearm, and if such a magazine were made with a very large capacity the resulting magazine/firearm system would be prohibitively cumbersome. 
This invention is a significant advancement in firearm magazine technology in that it produces a firearm system with a very large capacity (three to four times as many cartridges as a conventional magazine) and yet is compact, unobtrusive, and actually enhances the handling characteristics and accuracy of the firearm.  This invention is also a significant improvement on the related patents identified above.