I use a carbon fiber cleaning rod with a timney jag and a bore guide on my original 93 marlin. Muzzle to breach
Then take a small diameter nylon rod, drill and tap to jag threads. Heat and bend so you can clean the chamber from the breech. Takes some time but works
Then take a small diameter nylon rod, drill and tap to jag threads. Heat and bend so you can clean the chamber from the breech. Takes some time but works