RJK Ventures has a product that might appeal to shooters in California and other capacity restricted states. Called the Mag|Coupler, this device replaces the floorplates of AR-15 magazines to connect them butt to butt. The idea is to maintain the existing magazine capacity while putting a reload closer to hand.
While having the two magazines connected in such a manner may, or may not, improve reload speed, I do see another advantage to the system. It seems that a pair of 10-round magazines connected with a Mag|Coupler will fit perfectly into standard 30-round magazine pouches. For anyone who wants to set up a plate carrier with magazine pouches, you can use a pair of 10’s in each 30 round magazine carrier.
The idea of connecting magazines together is not new, nor has it really caught on with the majority of shooters. If you live in a capacity region this system might be of benefit while keeping you legal. It certainly seems more workable than the five magazine set up that FAB Defense introduced at the 2014 SHOT Show. While interesting, that rig looked a bit unwieldy.
If you are not worried about keeping to an artificially low round count, you always have the option of increasing overall capacity with something like this. Personally, I’d just rather have two 30-round magazines.