We learned that from the Japanese in WW2. They used 6MM that would only wound a GI. They knew that we did not leave our wounded like they did so every wounded GI took two able bodied soldiers off the battlefiled.
In the News/Activism forum, on a thread titled The giant, gaping hole in Sandy Hook reporting, USAF80 wrote:
“We learned that from the Japanese in WW2. They used 6MM that would only wound a GI. They knew that we did not leave our wounded like they did so every wounded GI took two able bodied soldiers off the battlefiled.”
Yep ...That’s the reason but that wasn’t really put into effect by US until Viet Nam ..We were still using the standard 30 cal used in M-1 and Springfields as well as machineguns during the Korean war and beyond. The reason was it was cost effieient. And if a supply depot was overrun and captured the ammo couldn’t be used (at least very easily) against US.