An Enhanced Magazine Designed to Feed .458 SOCOM
The .458 SOCOM is a big-bore cartridge designed to function in standard AR-15 upper receivers complete with a standard bolt and magazine. However, in reality, users have found that components designed for use with 5.56 NATO rounds aren't set up for perfect performance with this large-bore cartridge, and so CMMG addressed the issue with its MkW-15 Magazine purpose-built for the .458 SOCOM.
Each CMMG MkW-15 Magazine is based on the Lancer L5 Advanced Warfighter Magazine, which was the top choice for shooters of the .458 SOCOM. However, there was room for improvement, so CMMG engineers took the existing magazine design and modified the feed lips to better hold .458 SOCOM rounds without weakening the integrity of the design.
Since, at its core, the CMMG-modified Lancer L5 magazine is still a 5.56 NATO mag, users can fit 30 rounds of 5.56 NATO into it, which will function fine. However, the magazine will also provide premium performance when loaded with 10 .458 SOCOM rounds.
Due to the many state restrictions on magazine capacity we will not ship these magazines to individuals in the following restricted states: Hawaii, Maryland, Massachusetts, New Jersey, New York, California, Connecticut, Colorado, Washington D.C., Chicago/Aurora/Oak Park Illinois, South Bend Indiana.
Big Book Catalog, Issue:73, Page:074