I've just inherited an old Winchest Model 60 single shot .22 S-L-LR. The stock and exterior metal are pretty good, but the inside of the barel is aweful. The chamber appears OK, and the muzzle half of the barrel appears OK, but about the first 8" forward of the chamber is BAD. I've use CLP, Sweets 762, rust & blue remover, nylon and bronze brushes, but I still get brown rags pushing out. The lands appear smooth and shiny, but the groves appear black matte & slightly pitted.

Is there anything out there that will take out the rust better, or maybe just shoot it out?

The barrel may be leaded up. Use a course steel wool wrapped around an old brass brush so that it is tight to push thru. Fine steel wool won't cut the lead. Use Hoppe #9 and work back and forth. I learn this from an old target shooting gunsmith years ago. Cheap 22 ammo years ago would lead a barrel quick. You will not harm the barrel enough to worry about in this old 22. You can alway install a 22 liner and make it a shooter again.