ok, today i tried clr on a ss barrel - took off brake, took gun out of stock to be safe, ran a wet patch of kroil thru, then dry, then put a silicone plug in the chamber, and filled the barrel with clr.
Let it sit for 45min, muzzle up - straight up.....then carefully drained, put muzzle down, patched it with dry patches, then rinsed it out real good with windex, then kroil, then 2 dry patches & repeated kroil wet/2 dry till no dark carbon on patches.
Holy crap did it work - carbon simply disappeared. Carbon ring dissolved to nothing.
This is carbon that wipe-out, carb-out, butches, boretech eliminator, and hoppes with nylon brush would not remove. Some of these worked great with copper and crud, but didn't remove the baked on stuff.
I finished with some borebright on a snug patch, then cleaned it all out, and man, is it nice and shiny. Looks new.
Can't wait to shoot it now!