Beta C-Mag
The Beta C-Mag is a 100-round capacity drum magazine manufactured by the Beta Company. It was designed by Jim Sullivan and has been adapted for use in numerous firearms firing the 5.56×45mm NATO, 7.62×51mm NATO, and 9×19mm Parabellum cartridges.C-Mag is short for century magazine, referring to its hundred-round capacity. It has two drum units, each of which hold half of the cartridges inserted into the magazine. The latest version of the magazine is available with a transparent backing to allow the user to see the number of rounds remaining in the magazine. A C-Mag loaded with 5.56×45mm NATO ammunition typically weighs about 2.1 kg (4.63 lb); a C-Mag loaded with 7.62×51mm NATO ammunition weighs 4.77 kg (10.5 lb).
One such magazine adapted for the M16 rifle is used by the U.S. military. The magazine design, including drawings, is covered in detail in U.S. Patent 4,658,700.
Design
The C-MAG is a compact twin-drum magazine design that accepts up to 100 rounds of ammunition. It consists of two main components: the twin-drum storage housing, and an interchangeable feed clip assembly. The storage housing is standard and fits any like-caliber weapon. The feed clip assembly serves as an adapter for the specific weapon.