This can be accomplished by hand with a reamer, a hand reamer to be exact. These can be purchased, or rented from Brownell's.
The trick is take your time, use plenty of Cut Max, and check your work at intervals with Go/No Go guages.
"Rifle" magazine always has adds from these suppliers, and there have been a couple of articles over the years with excellent descriptions and instructions. You can get back issues from their web page.
A forum community dedicated to Sport shooters, owners and enthusiasts. Come join the discussion about optics, hand casting bullets, hunting, gunsmithing, styles, reviews, accessories, classifieds, and more!