Noob question here.....installed an ACE full size stock on my Superior Arms AR followed all directions,seemed a little loose but no more so than my other Ar ,went to the range today and experienced a bad FTE . Came home and took her apart and found the buffer retainer all chewed up and had come out allowing the buffer to push against the back of the bolt. Gonna order new retainer and spring,but any suggestions on what I may have done wrong installing the stock?  Just looking for input.

I'm guessing you have the Ace ARFX. I have a couple and neither one is the least bit loose, as you describe. Without knowing much more, I'd say you probably want to figure out why it's loose - it seems pausible that may have a bearing on your buffer detent coming loose.

Quoted: Noob question here.....installed an ACE full size stock on my Superior Arms AR followed all directions,seemed a little loose but no more so than my other Ar ,went to the range today and experienced a bad FTE . Came home and took her apart and found the buffer retainer all chewed up and had come out allowing the buffer to push against the back of the bolt. Gonna order new retainer and spring,but any suggestions on what I may have done wrong installing the stock?  Just looking for input.

There is a spring-loaded pin that holds the buffer in the receiver extension, is that still there?  Nevermind, RIF.

I have two AR's with ACE Stocks - both are very tight and sturdy.

+1.  My ARFX is rock solid.  No movement whatsoever.