Trust me, when the bolt is open you can tell. The bolt will be unlocked and the op rod handle will be short of closing. The M14used the same hold open feature and you definitely knew that you were empty. The M14 could be recharged through to top with stripper clips straight into the magazine. It isn't how, it is the message. I said "MAY have to hit the guy 2 or 3 times". Most fighting in Korea was at night. Hits decrease to ridiculous shooting at night. Even with flares, it is more difficult. When I was young, I worked with many WW2 Marines (This was in 1964, 19-20 years after the war), not many were impressed with the killing power of the carbine. I'm not so much knocking the carbine as I am knocking the lack of a hold open feature on the magazines. The Tarawa films show how the Marines were fooled by the magazines. Reading War Baby the ordnance dept modified 15 round magazines to use the hold open feature, I suspect to just let people know that it was an easy fix, but I suspect that as millions of magazines were being made, stopping production to await the new followers was just not in the plan.