After finally coming across one that developed a leak, my coworker Justin opened one up to inspect it’s viability for conversion it to run his future KJW GBBR external air.
Surprisingly, the space inside that would contain gas was smaller than expected. Loaded BB’s would double stack in a vertical column, rather than in a curved shape like most GBB M4 magazines. Though this design choice occupied a bit more usable green gas volume inside the magazine, the KJ V2’s still run quite well on these mags as well, from what I’ve seen.
Note the uniquely-shaped seal between the two halves of the magazine. Once again, differing from the old mags by quite a bit.
Well, that being said – the whole magazine itself is a different take on how to design a M4 GBBR magazine.