Every time a primer is shot, a trace of residue remains in the breech plug. The more you shoot, the more that trace builds up, eventually narrowing the size of the flame path. Looking through the breech plug, you’ll still see light but the hole will be lessened dramatically. As with the vent liner, it is difficult to come up with a absolute number. Since black powder (or substitutes) will require cleaning after each shooting session, it’s a good idea to get into the habit of inspecting the breech plug every time it is removed to clean the bore. Be sure to wipe dry and lightly coat the threads with any Mil-Spec 907E anti-seize compound such as Birchwood Casey Choke Tube lube or Kleen-Bore® TW25B. This will ensure that these parts will unthread the next time the rifle is completely disassembled. Use it very sparingly or it will wick into the barrel and wet the powder - causing misfires.
How often should I clean the breech plug on my muzzle loader?
