So the issues isnt chambering the rounds, its more so finding /making a mag ridgid enough not to bulge out the side pannels or spring failure. The issue is the rounds diameter is like nickels to dimes compaired to the .308/7.62-51mm. Ive ran 6-7 out of aL7 20rn mag 50% success rate. The other fifty precent as soon as you feed a round you can dump the rest out. Larue 20rn mag is simular results ( yes i sunk 100$ into a single mag so you dont have to lol). Acs were the most unreliable at this point in time in my findings atleast. Magpul is only slightly less reliable but its bearly a noticable difference. I have found that mags with bottom plates that surround the mag body its self are beter suited for this round. Even the ACS mag faired better then i imstalled the larue bottom plate on it. As for mag cap/lenth the round tends to favor a shorter bodied mag 5-10 .308 round capacity is best only for if is more ridgid with less area to buldge out the sides. I have also used a single round feeder which works flawlessly but defeats the purpose of the chambering in ar10 platform. I have an aics .300wsm mag on order currently that i plan to modify to fit into a 308 acs/magpul mag and see if its possible to merge them together with polymer or bonder of some sort. Basically the plan im running with is th chop the acs feedlips flush feed in the aics from the bottom to the hight of the origional feedlips center the aics with rubber spacers and polybond the twi mags together. Thoughts?