I went a little nuts a couple years ago and bought a muzzle and cylinder facing tool from Brownells. About $75 with a pilot for one caliber. I tried it on a rifle that wasn't worth too much, figured a gunsmith could take off a bit more and fix my mistakes if it didn't turn out. Actually it went very well. Very nice smooth and level muzzle and accuracy actually improved. One lesson; with this device you don't need to be too precise to get the initial hack saw cut at 90 degrees as the device evens it all up. Once you have the tool a muzzle pilot for another caliber is about $25. Use lots of oil and cut smoothly and with even hand pressure.
