I retract the Ackley comment, I cannot find the reference. If I remember properly the .276 clips were directional and could only be inserted one way. I don't think there was an AR-10 when the m14 was adopted, at least not when testing began.
I also wonder if the manufacturing technology was ready to produce the AR-10 in large numbers.
I also wonder if the manufacturing technology was ready to produce the AR-10 in large numbers.

