Well, I've been cleaning it with boiling hot soapy water. I clean it with that by brushing it out, pouring water down, brushing, and repeat. Then I start running patches through it until it comes out clean. I then quite a few dry patches through it to get it dry. Finally I soak a patch in Remington Oil and run it down the bore. I leave it dripping wet with oil. When I get ready to shoot it the next time I run a dry patch down to wipe the oil out and then load and shoot.

Now a few times over the hunting season where I didn't have boiling water I used rubbing alcohol to clean with.

I also have used some of the Wipe Out bore cleaner on I use on my rifles on it. Like after getting it pretty clean with the soapy water I've been using some of this stuff as it seems to get a little copper out and get it a little cleaner. If I use this I do it just like on rifles and let it soak, run another patch through, let it soak for a few minutes, then repeat until the patches are clean. Then once again after they patches are clean I will dry out the bore and coat it in Remington Oil.