Try scrubbing your barrel with sweets using a bronze brush. I know it will eat away the brush a little. Keep putting sweets on every 2nd time you poke it out the muzzle for several strokes. Get the barrel full of blue goop from one end to the other. Let it sit for 15 min. Meanwhile clean your brush with carb cleaner, and set that brush aside and only use it for sweets. Use should get about 5 uses out of it before it starts getting too loose in the bore. After 5 min. push a patch soaked in Hydrogen peroxide very very very slowly down the barrel. It should take over a minute to push patch through. When you get about 2 in. from the muzzle you will see it start to foam out blue and yellow gunk. Push it all the way through. Use a second patch soaked in hydrogen peroxide but a little faster. Then finish up with a couple of dry patches. I would be very surprised if you had any copper left. The hydrogen peroxide helps to suspend the copper in its liquid state a while longer until you can get it out of the bore.
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