I'm new to the AR-15 and have a problem, I purchased a CAR kit from J&T with a RR lower, followed the instructions and after awhile the gun locks up. I take it apart and find that the buffer detent has popped out.

http://www.hunt101.com/img/051911.JPG

by RR are you emaning Rock River arms or a Registered Receiver?

IF it's a post ban, you better ditch that stock if it's not pinned.

That said, seeing you are using a CAR stock, is it possible to turn the buffer assembly/stock in another turn? Typically there are 3 settings...turned in too far, turned in to little, and jsut perfect.

MY guess would be you don't have it turned in far enough.

1. Yes it is a Rock River Arms post ban lower
2. Don't know if the stock is pinned
3. I will try to turn it a few more turns
and thanks for your help

Well... I'll put it this way. If the stock collapses, you have a post ban assault weapon. As in ILLEGAL.

Now.... don't answer that question. but if the stock collapses, you might want to change it out.

I'm not tryign to get on your case in any way. I jsut hate to see good guys get busted because they thought they were obeying the law.

As for the buffer detent, you'll have ot back out on the nut a but and turn the whole stuck in another turn. Take the upper off the lower, remove the buffer, and take a look. You'll be able to see when it's in far enough.

I turned the stock one more time to the point that it covers the detent pin slightly, tried dry firing numerous times and seems to have fixed the problem. Haven't tried firing yet but will post updates and thanks for your help NAM.

P.S. the stock is pinned, no need to worry.

You did the right thing.  The buffer tube is supposed to cover part of the detent hole.  By design, that's what keeps it in the lower receiver.