6.8mm AR magazines

[LA_357SIG]

Are 5.56mm and 6.8mm magazines interchangeable? Holding them side by side they seem to be almost identical accept for the follower. Does anyone know why the standard AR magazine wouldn't work? I'm really just interested in the 20 and 10 rounders?

Or are most forums just referring to the 30 round magazines?

[TimP]

they will not work. The rails that run down the side of the mag are thinner for the 6.8 than they are for the 556. I'll snap a pic in a few for ya