A reliable “coffin” style magazine is perhaps the holy grain of high-capacity enthusiasts. While drums are certainly a proven technology, they often suffer from large volume relative to the ammunition contained inside which then causes other issues like uncomfortable shooting positions, inability to get into full prone, etc. Still, the higher capacity brings them out again and again.

Its a not so quiet secret that Magpul had previously worked on a polymer coffin magazine and through their work even patented an architecture for a quad-stack magazine with the internet and enthusiasts set ablaze when the patent went public in 2010. Unfortunately for us enthusiasts, the mythical Magpul quad stack was never to be and only Surefire’s offering is available to this day.

Magpul has always been tight-lipped on the magazine and points to the D60 as meeting the majority of the requirements by being high-capacity with minimal bulk. True, it is, but its not a coffin mag which at least did exist in Magpul’s R&D labs. Announced on March 27th on Facebook, Magpul finally opened up on why the magazine did not exist:

Quad Mag Prototype, 60-Round Capacity 2009
Shortly after the introduction of the original PMAG, Magpul began working on increased capacity solutions. The “Quad” or “Coffin” mag concept never delivered the reliability in rough handling and adverse conditions that we require from our magazine products, and so the design never made it into production. Lessons learned during this program eventually fed into the D-60 program.#MAGPUL#PMAG10YEARS#MAGMONDAY#PMAG

Nuts. LIke many commenters on their facebook page, I would take the coffin magazine over the D60 (which to Magpul’s credit, does work very well).