Hi Craig. I believe that is true providing we are talking about two barrels (one fluted and one unfluted) that weigh the same. Since a fluted barrel that weighs the same as an unfluted one would be a larger profile (assuming they are the same length), I think this is where the additional stiffness comes in.

    My physics is a bit rusty on root modulus strength formulas....I was too busy looking at this cute gal sitting across the row and one desk ahead of me ;).

   I don't think it's ever possible to add stiffness by removing material in a cylindrical object like a barrel.

   Not that fluted barrels don't shoot well...Roy Oines has spanked us plenty hard on quite a few occasions with that fluted tube on his red gun!   

    Hopefully someone with a better background on physics can help us out here... -Al