I have a ASA 9mm kit on a Bushmaster lower.  I bought it used about 10 years ago off the EE from a member in CT (Forgot your name, we met at a Italian / pizza place you worked near Corbins Corner,  IM  me if you are still around).  It has a postban fixed CAR stock.  My question is does the 9MM use a special buffer / spring?  My plans are to replace the "fake" CAR stock with a A1 buffer / stock assy.  I Emailed ASA with this question a week back, and haven't got a reply.  

Thank you in advance

OSA

A1/A2 tube will use plain old A1/A2 rifle buffer and rifle spring..

This is wrong.





Note that the buffer in a 9mm is usually twice as heavy as a normal CAR buffer.  In other words, your buffer is special in your fake CAR stock.  The spring in your CAR stock is a regular carbine buffer spring.
To use an A1 or A2 buffer tube with your 9mm buffer and carbine buffer spring, you will need to buy a spacer that slides down into the A1/A2 tube first.
This is an example spacer
http://www.riflegear.com/p-398-rra-9mm-stock-spacer.aspx
 Get your A1/A2 tube on with stock, put spacer in, then put in your old 9mm buffer and carbine spring.



An argument can be made that a regular rifle buffer and rifle buffer spring should work.  However, a heavier buffer (i.e. 9mm) is better for dwell time and keeping gas out of your face.  Further, it is cheaper to only get a spacer as opposed to a rifle buffer spring and a rifle buffer that "should" work.
 

astrafire,

Is it safe to assume, that I could buy a M4 6pos stock, and install it with my buffer and spring........everything should work??

Thank you for the info.

OSA

This is correct.