The enzyme I am talking about is called Hunter's Extreme Copper Melt. It is made in Canada and it works with a live, water-soluble enzyme that has been bio-engineered to literally eat copper,moly,powder residue, and lead almost instantly. A friend of mine was given a bottle of this stuff at the 2004 Shot Show and let me try it on a barrel of mine that usually takes 7-8 hours of scrubbing with cr-10 and Butch's. The barrel was clean with 8 patches! Needless to say, I have been using the stuff ever since. I don't believe in magic potions, but this stuff really deserves your attention, especially if you clean your guns often and are "anal" about it. I have put this stuff on a piece of barrel metal overnight for 3 nights and it made absolutely no discoloration at all. I then put a drop on a bullet and let it sit overnight. In the morning it had almost dissolved the jacket down to the lead. Of course, there are always some drawbacks to something this good. One is cost. This product is expensive. $30 for a 3.5 oz. bottle. You also have to gear up with undersized nylon brushes for your caliber because it is designed to work with an oversized patch wrapped around an undersized brush. And it has to be nylon because it will eat your bronze brushes for lunch. Another drawback is that since it is a living organism, it is possible to kill it. If you contaminate the supplied dropper with anything foreign and then stick it back in the bottle it will wipe out your $30 bucks. But if you can deal with these drawbacks the rewards are great. If you want to know more about it or possibly buy some, check out www.coppermelt.com. And no, I don't sell the stuff and I DIDN'T get paid to write this!!