When rebluing a barrel or any other metal part, it's important to do a real bang-up job of polishing it first. Let me show you how I go about polishing a barrel and getting it ready for bluing.
First I clean and degrease the lettering, apply some blue and rust remover, and then scrub out the rust in the bottom of the lettering with a nylon brush.

Now we can clamp the barrel in a vise for polishing. For this job, we're using cloth-backed abrasive in grits from 120 to 220. Starting with the 120 grit, I polish the barrel lengthwise using some type of block as a backer. Remember to tape over the lettering with masking tape first and stay away from it for now.

Switch to the 150 grit and polish using a shoeshine motion—this is called cross polishing. Then we'll go up to 180 grit, using the block backer and a lengthwise motion again.

Now we can remove the masking tape. For final polishing, we're using an inexpensive hobby lathe and the 220 grit abrasive. This will give us a nice consistent finish ready for bluing.

And that's how I polish up a barrel and get it ready for bluing.

-- Larry Potterfield