Don't be afraid to "chuck up" your cleaning jag in a drill and take it's diameter down a few thousandth's with emery cloth. It's been my observation that most people use a cleaning jag that's too big which just pushes fouling down the bbl. to clog the breech face.
This may seem like an odd question from someone who shot ML for a long time. But what is the correct size of cleaning jag. Other words how much smaller should the jag be in relationship to the bore dia?