Getting rust off a barrel...

I've got a project rifle that has some significant rust build up...what is the best way to get the rust off the barrel? What do y'all use?

bead blast and cerakote it

for those of us that own a bead blaster and trying to do this at home, I've found the following method to be painfully slow but effective and safe.
I take a standard #2 pencil, sharpen it, lightly coat the rust spot with oil, dip the pencil lead in a little oil, gently rub the rust stop with the pencil, wipe and repeat several times until it's all gone. the carbon in the lead is a very mild abrasive that cant rub out much other than very superficial surface rust.
Then again, I've only dealt with this a very few amount of times in relatively small spots.

If you're not looking to re-do the finish, check out this scouring pad looking thing:

http://www.frontiermetalcleaner.com/

Pretty good product for slight rust and best used dry. Apply only slight pressure and blow rust away as it falls off. Oil your part afterward to prevent new rust.

I bought one at a gun show, but don't expect to find it at Academy or any store like that. It does work good on bluing, but it might discolor case hardening.

If it's pitted then
If it's just surface rust #0000 Steel Wool with oil, take it slow.

This. You'll be shocked how much rust you can work out this way.

A spray-on finish like Moly Resin will adhere much better to a surface that's been blasted with an aluminum oxide medium or something similar. Bead blasting peens the surface and makes it too smooth, and the manufacturer spells this out in the user's guide. I haven't used Cerakote or Duracoat, but I would imagine the same applies.

Thanks everyone! I used the #0000 method and it looks amazing! Will post pics when I finish the entire project!

0000 steel wool is my friend for a whole lot of gentle cleaning projects. Add a touch of oil when polishing up softer metal parts. A lighter touch for a longer time will keep you out of trouble better than getting in a hurry and applying heavy pressure.

If your working on other than hard metal switch to bronze wool especially with wood. With wood if you leave behind some fine pieces with steel they'll turn into little tiny brown freckles when they rust it's not an issue with bronze.

now that you have the rust off, get an old toothbrush and CLP. Brush the CLP in to the barrel real good.

go online and check out GIBBS penatrent oil , you will be impressed