What is the "correct" way to use a range rod to dial in a barrel? I was setting a barrel up for muzzle threading and dialed in the 4 jaw first, then moved the dial indicator to the tip of the range rod and dialed in the spider. However when I went back to check the 4 jaw, it was now showing more than .005 of run out. I had it down to .002 before. Is there a correct way to do it?