liquidorange

There really is not much of a problem with any breech plug when shooting regular 209 primers and any black powder or black powder sub - other than BH-209.

When shooting BH with the very high pressure 209's like the Federal 209A or the CCI-209M as recommended by Western Powders - the flash channel in the breech plug will fill with a hard carbon. To clear that carbon most folks use a drill bit that they turn by hand to remove the carbon from the channel. This carbon builds as you are shooting and at the range to maintain accuracy you may have twist the carbon at the bench.