308 SBR - Parts Sourcing

[homerjays]

I currently have one of the newer Armalite 16", AR-10 rifles that uses the Pmags. I am thinking of trying to build an SBR upper for it. I can't seem to find a place online to source barrels. My google searches normally only turn up 16-24" barrels. Has anyone purchased a short barrel that they would recommend or know of a good place for sourcing these types of AR-10 parts?

 

[Crosshair]

Rainier Ultra Match 12.5" https://www.rainierarms.com/?page=shop/detail&product_id=3951

Cmmg 12.5" SS Barrel Sub-Assm, 12.5" MC 416SS SBN, 308 Win