Im pretty sure it could be done, but like Intruder says might cause some problems to pop up. Most barrels that are fluted are done before they are rifled and chambered to allow for stress relief. Even though they will be machined in, the barrel will still need to be removed, so thats an added cost, might put stress or curvature to the barrel that will need to be relived, another cost to consider. I would check with a smith before I made up my mind. Im with you, the do look cool and add a bit of surface area for cooling the barrel, as well as taking some weight off. Just things to consider.
Sage