I have an 03 springfield that wears a 18" 06 barrel. I have often thought of re-boring that one to the whelen myself. I like the extra thump and the larger wound channel it would offer. But again, after pricing barrels, it would be roughly the same price to just get a new barrel. But by the time you figure in a gunsmith, if you send it off, I think you will still come out a little cheaper to do it by re-boring. Around here, the prices range from 60.00 on up to chamber and install a barrel, but the extra cost of anything beyond that would add to the cost. In this instance of what the OP is asking, in all honesty I believe he would come out on the better end if he just installs a new barrel.