OK so to finish my first AR build, I removed an A2 stock from a RRA lower receiver and replaced it with a mil spec buffer tube with a magpul CTR stock on it. When I screwed the buffer tube on to cover up the buffer retainer pin, the tube would only cover a small portion of the detent spring shoulder. Unfortunately, if I gave the tube another full turn, the tube would come into contact with the nipple on the retainer pin before I could completely rotate the buffer tube. After reading about it online, some people said that I should leave the buffer tube as is and not worry about it. Others said that the retainer pin could pop up into the receiver during operation. I was wondering what you guys think I should do. here are some pics.