It will only hurt the gun if you notice the accuracy declining. There are some experts that believe that "burnishing" the bore with copper is far superior to removing every speck of it. This is supposedly supposed to smooth over those imperfections in the barrel.

I personally don't know about that. To mehaving copper on copper in your barrel can only lead togalling.

I'm such a freak that I wouldn't be able to sleep util the thing was clean.

I wish I could tell you how to get it out. My gun has "burnished" lands near the end of the barrel and it still shoots sub 1" @ 200 yards.

I had another gun I was using for work that was super accurate and I removed all the copper out of it and it didn't shoot worth a crap until I'd put about 20 rounds through it.

So personally I don't worry about it. If the bore looks good and it's shooting good I leave it alone.