Top Japan surprised us in 2011 about the M4 Carbine Electric Blowback AEG with its shell-ejecting feature. But it seems that the uptake was slow since many would not bother themselves of spending on shells just for skirmishes (or picking them up after for re-use). Now they have released the cartridge-less eversion whilst maintaining the blowback function and players won't need the cartridges/shells for their magazines.

Learn more about this by reading the review at Hyperdouraku (in Japanese) a video of it being fired below.