Naval Jelly works well. Coat and wait ten minutes. As does a Boric acid soak, the "Roach Powder" found at a store like "Dollar General". Five heaping tablespoons per gallon of hot water. Again, a ten minute soak. After using either product, a scrub down with a green scrubby pad will remove all the bluing.

Afterwards, I like to sand the barrels when they're in a tray of water, it makes the wet/dry sandpaper work more efficiently.

Make sure you degrease with acetone before either treatment.

Here's a thread with lot's of good info:

http://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=396418&page=1

PA24 really has the prep down to a science.

Regards
Ken

Last edited by Ken61; 04/15/15 08:55 AM.
I prefer wood to plastic, leather to nylon, waxed cotton to Gore-Tex, and split bamboo to graphite.