Pruts, I agree with moat everything said:
1. Short strokes, when ring is contacted don't bull through, peck at it - it doesn't take that long
2. All barrels build up some sort of crud ring eventually, no matter the ignition source
3. Try CCI or Rem 410 primers, cooler ignition
4. Instead of a spit patch try a patch damp with a BP cleaner and then dry patch
5. Use a bore brush as needed to break up what the patch doesn't
6. Check with TC, and see what generation of breech plug you have, they are on their third and from reports I have read it seems to lessen the crud ring