My detent/buffer retainer wants to keep coming out when the bolt cycles.  Is there something that holds it in?  There is a spring under it and it comes up into the bolt and gets pulled into the chamber.  Any suggestions?

Above under the "information" button is good info......

FWIW ya need to screw your buffer tube in "until" it captures the buffer tube retaining pin.

Mike

ETA - this is from there, and whether ya got the A2 stock or the collapsible, you still need to make certain it's installed properly, check the "assembly" under the button listed above.....




BTW, always make certain of what your doing; as this type of problem is generally not the rifle causing the problem, but modifiers doing things they have not researched properly, ie. "a loose nut, between the seat and the steering wheel"

Your buffer tube secures the detent and it is backing out on you. This is somewhat common. You need to torque the buffer tube properly. Sometimes I have found a dab of *blue* loctite on the threads of the buffer tube is needed. Later, if it is needing to be removed, normal tools should loosen it. If not, a gently dab of heat will definately remove the loctite.

Thanks guys.  I didn't know the buffer tube held it, as it didn't "pop" out when I unscrewed my stock buffer tube, it stuck in there a little, then "popped" across the room.  Since it didn't pop out right away I figued there was something else holding it in, other than the tube.  Should the buffer tube be completely against the raised portion of the detent, tightened snugly against it?  Thx.

Build it yourself

Crud could of been keeping it down.