I've used Shooter Choice for quite a few years now. I recently got some of their Copper Removal formula. It is working really well for what it is intended. If you're cleaning revolvers used with lead bullets, the original Shooters Choice is great. For my rifles, I use the Copper Remover in conjunction with the Remington Bore cleaner. It gives a real double whammy on bore fouling. I have seen a dramatic improvement in a couple of my guns since I started using this combination.
One is a custom 98 Mauser in .257 Roberts. I got the gun real wet in a down pour in the 1992 deer season. I cleaned the gun really well, even taking it out of the stock. I put it up in my attic for 2 weeks while I went on an out of state vacation the next summer. Come deer season, I didn't clean the gun before shooting it to check zero- instant pitting !!! The accuracy of the rifle dropped off noticealby over the next several years. I was about to scrap the barrel, but noticed a lot of copper in the muzzle. After scrubbing several times over a couple of weeks, I took it out and shot it; accuracy was equal or better than before the rusting !!! Only problem is that after 20-25 shots, the fouling comes back- but no problem, it's a "mountain rifle" feather weight, and that amounts to about a years worth of shooting. So after every range session and successful deer hunt, it gets the Shooters Choice treatment. Forutunately, this rifle shoots the first "cold and clean" shot to same POI as fouled.