Just got all the peices in for my RRA M4, so far I have the Upper and complete lower with a Magpul M93B stock. The only thing I think I'm missing is the Buffer and Spring. Can someone tell me which one I should get?

I guess I'll be ordering straight from RRA. Here are my options:

AR0107A  107 - Buffer assembly, CAR  
AR0107AH  107 - Buffer assembly, CAR heavy  

AR0072A 72 - Action spring, CAR
AR0072B  72 - Action spring, standard

Which one of these am I stuppose to get??

Also, I kind of put the rifle together without those peices now it seems the bolt is caught somewhere in the stock (most likely the buffer retainer). Is there an easy way to get it unstuck?

You want the CAR action spring.

I would suggest a 9mm buffer with the M4 (carbine gas system) upper, though. It will improve funtioning, and the rifle won't beat on itself as much.

WIZZO

Thanks, are you talking about one of these?

http://www.rockriverarms.com/images/9part3.gif

9MM0107 9mm Buffer

Would I need the spacer too?