Any 2 scoped rifle case will work.
I have had as many as 8 scoped barrels in mine along with 1 shotgun barrel.
If that is to large then a single scoped rifle case should hold your three scoped barrels if you flip ends and turn each barrel over with the third one in the middle.
By the way, 9 barrels is about all one can pick up and carry in a case.
Mine has the metal reinforced edges and is airline approved, not a cheap plane plastic one.
LONGTOM