Hollis

Welcome to the forum, I trust you will find it a great source of info and good advice.

Cleaning brushes and jags for the large bore rifles can be obtained from David Little at Kynamco in Mildenhall, suffolk.

David has brass jags made for upto .600 bore and phospor brnze brushes to the same bore size all made to fit the standard male PH thread. I use them for my own rifles and they work just fine.

As for cleaning copper fouling the same solvent that work for your smaller rifles wil be just fine also