Not having gone to war with a M1 I counldn't give any first hand information. Being on the range with one on many occaisions I will say that when M1 clips hit solid objects they are noisy. With that in mind I could see that, at certain times, it would not be good to hear that sound. I wouldn't want to be in room to room combat inside a house and let the opposing force hear that thing hit the floor. Full pitched battle I wouldn't think would matter, as said that's loud anyway. If you've ever been in infantry exercises or in a war zone its becomes clear that sometimes the smallest thing can give you away or make clear your attitude and/or position. The common ones are talking, smoking and light issues at night. With that in mind I could see where a clip from a M1 banging around may be an issue at some point. I would also hesitate to call any vets story a myth or B.S.