I'm sure this has been covered before, but here goes:

If you file the ATF paperwork for a SBR (I'm thinking 14.5" M4 upper) does that take the rifle out from under the AWB because it becomes an NFA firearm? I know this is the case for a machinegun, but haven't seen documentation WRT other NFA items  such as suppressors, SBRs, and so on. Seems like a cost-effective way to build a post-ban M4gery with collapsible stock, etc. given the cost of a pre-ban (esp. Colt) lower.

Anybody got the dope on this one?

You won't be able to have the evil features on your SBR AR until after Sept of next year if you  start with a new AR.  If you use a pre-ban, it was already an AW and you can have the dreaded threaded bbl, collapsable stock, etc.

pazzo is correct.  Even though you register it as an NFA SBR it does not exempt it from the AWB.

However, an RDIAS does exempt it while the RDIAS  is in the weapon.

Or, as pazzo mentioned, wait one year til the stupid ban, errr, AWB sunsets.