I don't know if this was already said, but if it wasn't here is a guide I found to polishing the stock barrel on the Pro/Carbine (probably will work for other guns too.)
Polishing: Stock Barrel
What it does: Reduces friction in barrel.
-Drill with drill bit (bit size can vary to fit screws thread size)
-Plastic coat hanger
-Wood screw (screws head should not be larger than the diameter of the coat hanger)
-Mothers Mag & Aluminum Polish
-Hacksaw or cutters of some sort
Note: This gets really messy.
1. Take the plastic coat hanger and cut the straight part of it out.
2. In one end of the coat hanger, tap a hole for your screw with the drill bit.
3. Get just enough cloth so that it fits snugly in the barrel.
4. Screw the patch of cloth onto the top of the coat hanger.
5. Take the electrical tape, and tape over the ports in your barrel.
6. Insert the end of the coat hanger that doesn't have the cloth on it into the drill.
7. Apply a very generous amount of the metal polish into the barrel and onto the cloth.
8. Now crank up the drill and polish the barrel until it has a mirrory shine on the inside.