I just did that yesterday. The jaws on my 3 jaw chuck wouldn't open far enough to grip the outer diameter, so I mounted the 4 jaw chuck in my lathe and reversed the jaws.--this gives a much larger diameter capacity, but requires that you use a dial indicator to center the piece in the 4 jaw. Then drill a pilot hole, then go up in 1/4" steps to your largest drill held in the tailstock chuck. Then mount a boring tool in the toolpost and spend an hour boring out to the desired size. If your o.d. was roughed out slightly oversize before you started, then remount the 3 jaw chuck, expand the chuck jaws to grip inside the hole you have just bored, and turn the finished outer diameter. The ring I made was 5.54" o.d. with a 3.54" center hole.---Brian