Now, this is only my thoughts and there is no proof of what I am thinking, but think about it. Now management says produce 10,000 rifles per month. Well one part of plant is assembling triggers, receiver covers(engraving), bolts and barrels. Now when it comes to assembly, all parts have to be hand stamped or engraved. Would one assembly line be able to meet production, probably not. Now if there were 5, 10, 15, 20 or more then it would be possible. What I am thinking is that if there were parts that were made, but they knew were outdated, they would use them up and then upgrade. Now would they tell all the assembly lines to use up existing parts and then use the newer parts or would they say #1-#19 production lines use newer parts and #20 production line to use outdated parts until they are used up. Like I said, my thoughts only. I thought about this when discussions about the spike bayonet used in early 1950.