Patent ID: 8291806

Claim:
An ammunition magazine for holding and delivering a plurality of cartridges, the magazine comprising: an outer housing having a substantially cylindrical inner wall surface defining a longitudinal axis; an inner support member mounted within the housing and having a substantially cylindrical outer wall surface which is concentric and opposing said inner wall surface of said housing thereby forming a gap between the cylindrical inner wall surface and the cylindrical outer wall surface; a helical ramp disposed within the gap and having a concentric axis to said inner wall surface and said outer wall surface, said helical ramp extending from said inner wall surface of said outer housing to said outer wall surface of said inner support member; said helical ramp forming a helical gap within said gap, said helical gap configured to receive a plurality of cartridges such that a longitudinal axis of each cartridge is oriented radially of the inner wall surface within the helical gap; and a drive mechanism for advancing the cartridges along the helical ramp.