I bought THESE for my 5.56 and my .308 rifles. My reasoning was simple. Due to the modifications I did to my rifles, I have to do complete receiver separation every time I need to do maintenance. My 5.56 has a CWS that locks everything up, and my .308 has a Law Tactical folding stock adapter. My price at Brownells was cheap enough for me to buy several sets. I don't think they are for everyone, but they work for me.