First off let me say that I recieved my RRA midlength upper with ss bbl and quad rail free float tube last month.  Outstanding quality and a quick turn around time.  You have a customer for life.

I will be purchasing one of your lower recievers soon and want to install a Magpul stock.  I need to purchase a CAR length action spring and a CAR buffer.  But which buffer?  Your site lists two:

AR0107A  107 - Buffer assembly, CAR  $10.50        
or the
AR0107AH  107 - Buffer assembly, CAR heavy  $20.00    

Why two differnt weights and which do need for a midlength that will shoot regular spec ammo?

Thanks for your help and all of the great info I get from your RRA forum.   P.S.  Sorry, couldn't help myself with the dancing banana.

A regular CAR buffer should be fine for a mid-length set up.
The heavy CAR buffer is primarily for slowing your rate of fire and improved performance for full-auto guns.
Thanks.
Steve/RRA

Thanks, Steve.