Glenn
For the most part , on a Traditional muzzleloader , the breech plugs are not removed for cleaning . About the only reason one would remove the breech would be a stuck load that cant be pulled or to work on the breech itself .
With your Pedersoli , it has what�s called an improved breech Or patent breech design . As such you flash hole liner , while screwing into the barrel wall , also screws into the breech . This ends up locking the breech plug and must be removed prior to attempting to back the plug out . The other issue that can happen is that because the flash hole and on percussion rifles , the drum bolster threads are tapped after the plug is set to the barrel. This raises burrs and thus you can bugger up the plug and barrel threads.
Though notably Pedersoli normally does a good job of cleaning those up . So the issue isn�t as great as say on a traditions or CVA rifle .
When cleaning your rifle , you do need to use a small 17-22 cal bore brush so as to clean out the breech
here are some photos of what the breechplug looks like on a blueridge , frontier ........ rifle
This plug I removed for a customer who was experiencing inconsistent ignition of his blue ridge flintlock . IE it would flash the pan but not ignite the main charge . Once the plug was removed , it was very clear why .
This is what the plug looked like after it was cleaned up .
notice how much fouling had built up on the breech face . thus restricting the powder from entering the breech.