Nope. It is unobtainium.

The Green Mountain barrels were made in 1/12 because the retro crowd NEEDs to have an authentic 1/12 despite engraving fake colt marking on NoDak lowers. The citadel A1 barrels are unchromed 4140 and no one has tested them for accuracy. I have actually held in my hands an FNMI barrel that was A1 profile 1/7. The SC based dealer told me FN makes A1 profiled A2 rifles for an asian nation. He wanted $450 for the barrel and $650 for the barreled upper. I regret not buying it to this day.

If this is what you REALLY want, just about the only way to do it is have Adco re-profile an A2 and install a .625 fsb. It wont be cheap. Probably $400 by the time it's all said and done.

If I could find a reputable report of the citadel 1/9 A1 barrel's accuracy I would buy one of those and send it out to be melonited.

Their site is down right now, but check out Fulton Armory. They have an A1 style rifle w/ 1x8 rifling from Criterion barrels. Kind of interested in this one myself.