Patent ID: 8850732

Claim:
A magazine for a firearm, comprising: a magazine shell having a first end, a second end opposite the first end, and a plurality of sidewalls between the first end and the second end, the first end having an opening and configured to attach to the firearm, the second end including a bottom plate; a main magazine spring having a first end and a second end opposite the first end, the second end of the main magazine spring coupled to the bottom plate of the second end of the magazine shell; and a deformable magazine sidewall spring received in the magazine shell and fitted along an internal surface of the magazine shell such that the deformable magazine sidewall spring provides side support to one or more ammunition cartridges when the one or more ammunition cartridges are held in the magazine shell and in contact with the deformable magazine sidewall spring by deforming and exerting a first force on the one or more ammunition cartridges in directions generally perpendicular to the sidewalls of the magazine shell, wherein the magazine shell includes at least one feeding lip extending, with a curvature, from at least one of the plurality of sidewalls at the first end of the magazine shell, wherein the magazine shell further includes at least one reinforcement groove that extends longitudinally into the curvature of the at least one feeding lip, wherein the deformable magazine sidewall spring has an outer surface contour similar to that of an inner surface of the sidewalls of the magazine shell, and wherein the sidewalls of the magazine shell includes one or more reinforcement grooves, and wherein the deformable magazine sidewall spring includes one or more grooves corresponding to the one or more reinforcement grooves of the magazine shell, the one or more grooves of the deformable magazine sidewall spring providing side support to one or more ammunition cartridges when the one or more ammunition cartridges are held in the magazine shell.