Sent to both Bushmaster and Aero Precision asking if they thought opening up a .308 boltface sufficiently to fit .30-30 would be a problem; apparently they just ignore questions they don't want to answer.
Son had an idea on magazines: put a guide internally on each side to make it a single-stack, feed lips modified appropriately. That's a definite possibility.
I'm going to have to start making a list of parts and see just what it would cost to build. Or start looking for a used or new AR-10 and see if that'd be cheaper than building from scratch, then add barrel, bolt and mags for the new cartridge. Although in this case it'd be 'modify the bolt'. Another idea from son: if get a complete AR, shorten the barrel to suitable length to change to a carbine-length gas tube and rechamber it.
I need to make a list. After I hit the grocery store and library. Speaking of, just finished Ancient Encounters, about Kennewick Man. Interesting read. Reading this, well, I remembered the Corps of Engineers not exactly covering itself with glory in its integrity, the information I hadn't seen before makes that even worse. And some of the tribes need to be told to piss off when they try to claim remains that far predate their existence in an area. And have much-different racial characteristics.