Rick
Rainier Arms website shows this 24" barrel as labeled for Armalite and in stock.
http://www.rainierarms.com/rainier-arms-ultramatchtm-308-barrel-24-6560Website doesn't have much info past that.
I have their 20" 308 barrel and it is sub moa to 300yds with federal gold medal match and with my handloads. Never shot it for groups further then that.