I was putting together a .308 dpms lower for a rifle I'm building and ran into a problem. The screw for the bolt catch mechanism which appeared to be a 1/16" allen head seemed to strip out (not the threads the head). I turned it all the way in and was NOT putting a lot of pressure on it and it just kept turning. So, its in, but it feels kinda wierd not knowing whats up. I tried standard and metric sizes before putting it together in the first place and it seemd 1/16" was the correct size....