So this is my first ofical posts, I'm glad I found you guys and in the future I hope to be of help but at the moment I need your help. While replacing the hand guard on my new national match M1a I decided to examine the markings after reading up on the history of TRW. I was quite surprised to find the firs part of it was ground down. I asked my friend whom I got it from and he was unaware and had not noticed. He did tell me that his father built it for his birthday in 1983 so that's all we know so far. He is going to try and track down the receipt, until then you guys have any idea what's up with my barrel?