Beta C-Mag

The cartridge column splits at the juncture of the feed clip and the housing to distribute the ammunition evenly into the drums in two concentric rows.

[3] 9×19mm Parabellum 5.56×45mm NATO (STANAG magazine with Mini-14 compatibility) 7.62×51mm NATO A test in 2003 by U.S. Army soldiers in Afghanistan found the C-Mag unreliable in simulated combat conditions and reported frequent failures to feed among the issues;[5] likewise, British Armed Forces trials found that the C-Mag did not give reliable performance when loaded with British-issue ammunition.

In November 2008, the U.S. Army Experimental Task Force (AETF) at Fort Bliss, Texas, evaluated six Beta C-Mag magazines.

Additionally, two magazines with black covers were evaluated with M249 light machine guns in controlled burst and rapid-fire scenarios.

These also performed without "issues", according to the memo, which also notes that soldiers "had only positive comments" about the C-Mag magazines during the After Action Review (AAR).