Well just a cool side note my M4 will hold seven in the tube, one in the chamber, and one on the shell lifter for a total of 9... All you need to do is load the tube, drop one in the chamber, and drop one on the lifter holding it down as you close the bolt... I heard about it on AR-15.com and it works.. I've not fired it from this position but it performs fine with orange training rounds.. just fyi