US Patent 8061071 Ammunition magazine with four ammunition stacks

The present invention is a high capacity, non-drum magazine. The high capacity magazine comprises a broad general storage area capable of holding four staggered stacks of ammunition, a unified follower on a spring system biasing the follower and associated ammunition, a central partition a barrier separating two dual staggered round stacks and around which the follower will pass, and a transition area between the feed end of the magazine and the storage area. The spring may be a composite spring system, made of two springs joined in series, or a single, variable constant, spring.