Harbor Freight has their deluxe Inspection Scope (bore scope) on special and I bought one and it ended up at $208. I ckecked both my 45-70 black powder rifles (original Rolling Block and a new Sharps) and there was a bit of lead in the lands. I generally use #9 and bronze brushes also but then I tried the "Chore Boy" method and wrapped some of one of the copper pads around a brass brush and ran it in a drill with some #9 and then some patches and the first ones were really black. The ones a few days before had come out clean after several passes! A recheck of the borescope showed a really shinny bore with nothing in the lands!
Here's the link:
Digital Inspection Camera with Recorder
The cashier gave me their 20% discount on top of the sale price AND I had a coupon for another free flashlite!