I agree with BobinNH, BSA, Blackdog and others who have praised the pre-64's factory barrels. As far as I'm concerned, the only reason to rebarrel would be to switch calibers, or lighten up a gun that has the standard weight barrel on it. One nice thing about the pre-64 barrels, besides their accuracy, is that all of them that I have owned were very smooth and cleaned up fast with Montana X-treme solvent.