I can only imagine that would cost more than sending a frame off for fitting. The best solution for this is to have 2 or more Handis. That way one can always be at the factory being fitted with a new barrel while you lovingly cradle, caress and fire the other.
The other part of this is that there is so much overlap in the product line that 4 or 5 barrels will give you all the performance that can be had from a Handi. All one really needs is a 223, 30-30, 30-06, 357 Mag and 45-70. One might add a 243 or 25-06 if desired, but this list covers the practical performance level being offered by H&R/NEF. A non handloader might want to add a 22 Hornet, but most people these days are doing less with more, relegating the 223 to cover all aspects of 22 centerfire play.