Depends on the rifling. I've got a couple of steep cut rifled .22's that will foul with lead from match ammo. These get a few passes with a phosphor bronze bore brush when groups start to open up. The shallow micro/multi/ackro-groove type rifles require nothing more than a tight patch over a button jag. I likw the Dewey coated one piece steel rod- those sectionalized aluminum rods should be destroyed. I've yet to see one in any caliber that doesn't abrade the edge of the chamber....
Regards,
Doc Sharptail