Try this: Put a rudder stop in the end of the barrel. Mix in a small cup 50% Hydrogen Peroxide and 50% viniger, pour in until it completely fills the chamber and let sit for 20 minutes then dump out and rinse with the remianing solution, run a bore brush through a couple of times and finish with a bore snake. I do this about every 2000 rounds. This take out all the leading and doesn't hurt the barrel. I've put 10's of thousands of rounds (MasterBlaster) thru my Glock and my barrel still looks new.
