Hey Yall, Ive spent most of the last year working on my M4 and its coming down to the last few steps, as nice as that sounds this problem keeps popping up. I replaced the upper receiver of my M4 with this one: http://www.evike.com/product_info.php?cPath=25_95&products_id=34615 . The threads for the delta ring has this weird notch cut out of them ( Pic coming later) so that when i get it fully tightened down all I have to do is give it a tap with my thumb and the delta ring comes loose so that i have to tighten it all the way down again. My delta ring is the standard SRC type, like this one: http://www.evike.com/product_info.php?products_id=28875 . any ideas on how to fix this?