The Netherlands Maritime Special Operations Force (NL-MARSOF) are planning to purchase a new carbine chambered in the non-NATO standard 7.62x35 mm (300 BLK), with a formal tender being launched by the Netherlands' Defence Material Organisation. The tender is the first publicly known tender for the purchase of a 7.62x35 mm chambered rifle by any military. In total, the Dutch naval commandos are looking to buy 195 select-fire carbines and 1.82 million 7.62x35 mm cartridges (1,345,000 ball, 244,000 subsonic, and 231,000 lead free frangible).
Back when I was well enough to pick up brass, I was encountering many more 300 AAC Blackouts laying on the ground than before. It does seem to be gaining in popularity, despite its cost and the reason lies in its terminal ballistics, I think. This is what I was getting at when I described the upgrade of the current M-4 as "lipstick on a pig." The 5.56 does not seem to me to be the best infantry cartridge we could field. It never has. It is, thanks to Robert McNamara and the dead hand of the Army procurement system, what we still have. (I also have never liked the gas system of the AR, since it craps where it eats, making fanatical cleaning an absolute priority.)