A friend of mine gave me a RR 9mm upper to try out, it wouldn't fit his bushy lower for some reason.  I tried it on my RR lower, and low and behold, the same problem.  The bolt won't return all the way forward.  Neither of us have any experience with 9mm uppers, is this normal?  are we doing something wrong?  is there a release for the bolt?

Please help, I can't remove this upper because the bolt is locked back into the stock.  How can I remove the upper?  And what needs to be repaired?

Thanks

Push out the take down pins, and pull the upper off the lower to solve your lock back problem.

Second, the carrier/bolt is sticking on the hammer (hammer bind).  If this is a Colt style upper, you need the semi-auto modified 9mm hammer to allow the upper to function.  

I'm not on my own computer, but can someone post a link to the Bigger hammer section of the hammers to show him the mod he need to do to the hammer to have it function the rifles.

Tweak, thanks for the hand/post.

The way that I read his post is that the pins both fit correctly, but the problem that they ran into on both of the rifles is that the carrier/bolt is sticking back due to the hammer bind, hence not fitting their uppers (function, and not fit).

But then again , been wrong nd the past, so who knows.