I recently acquired an Armalite AR-10 B-series rifle from my brother, and I'm trying to identify what it's stock configuration was.
Looking at this amazing post:
Is there a way that I can identify exactly which rifle I have and what it's original confuration (buttstock, forend, sights, etc.) was?
My particular rifle has a US329XXX serial number, "AR-10" marking, 20" bbl, M4 feedramp cuts on the upper receive and chamber, military trigger, A4 flat top, rifle length gas system, and the gas block has what looks like only a single picatinny cut across the top.
What else should I look for?
picture for reference: