Editing Beta C-Mag (section)

{{Short description|100-round drum magazine}}
[[File:Beta C-Mag on M4.jpg|thumb|300px|A Beta C-Mag undergoes field testing on an [[M4 carbine]]]]

The '''Beta C-Mag''' is a 100-round capacity [[drum magazine]] manufactured by the Beta Company. It was designed by [[L. James Sullivan|Jim Sullivan]] and first patented in 1987 and has been adapted for use in numerous firearms firing the [[5.56×45mm NATO]], [[7.62×51mm NATO]], and [[9×19mm Parabellum]] cartridges.<ref>{{cite web |url= https://betaco.com/products.asp |title= The Beta Company. BETA MAG C-MAG. 100 Round Magazine C-MAG Products |website= betaco.com |accessdate= 2015-04-14 |archive-url= https://web.archive.org/web/20160921054849/http://www.betaco.com/products.asp |archive-date= 2016-09-21 |url-status= dead }}</ref> ''C-Mag'' is short for ''century magazine'' (The letter '''C''' is also the [[Roman numeral]] for the number 100), referring to its 100-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.<ref name=autogenerated1>{{cite web|url= http://www.defensereview.com/ultimax-100-mk4-best-choice-for-usmc-infantry-automatic-rifle-iar-video-clip/ |title= Ultimax 100 MK4: Best Choice for USMC Infantry Automatic Rifle (IAR)? Video Clip |website= defensereview.com |first= David |last= Crane |date= 2006-03-17|accessdate= 2015-04-14}}</ref> A C-Mag loaded with [[5.56×45mm NATO]] ammunition typically weighs about  {{Convert|2.1|kg|lb|abbr=on|lk=on|sigfig=3}}; a C-Mag loaded with [[7.62×51mm NATO]] ammunition weighs {{Convert|4.77|kg|lb|abbr=on|lk=on|sigfig=3}}.

A version adapted for the [[M16 rifle]] is used by the [[United States Armed Forces|U.S. military]]. The magazine design, including drawings, is covered in detail in {{US Patent|4658700}}.