Jav-clean the gun all over with Hoppes, use Hoppes liberally with a copper bore brush making 8-10 passes. Then run wet Hoppes patches 3-4 times through the barrel. Follow that with dry patches till they come out clean. Last step: Run a very wet patch with CLP on it through the bore and stand the gun on its nose on some towels. You will be amazed at how much more CLP will pull out the bore in a week. Run a dry patch down the bore in a month and see what comes out
This is just my method, I am sure there are other ways to skin the cat. I know this is choppy, had to type fast - I have honey do's to get done.....hope it helps.