Sorry, but the only way to prevent copper fouling is not to shoot it.
As a general rule of thumb, the more velocity, the more copper gets left behind (all other things being equal, like barrel quality). A good high quality, hand lapped barrel will go more shots between needing cleaned, and also clean up easier and quicker, but they all need cleaning at some point.
If you're having a tough time getting it clean, try either the foaming bore cleaners (those are the bomb), or try a chamber plug (Sinclair's sells them), and literally fill the barrel full of good solvent and let it stand for 30 min or so, then pour the solvent out and swab with patches.
I've used both those methods for a minimal scrubbing type of clean.
Bookmarks