I have a stainless tc encore that needs a new spring and firing pin .I took the screw out that holds it but can't get the firing pin out .The spring went bad and the firing pin rusted in place .I guess you have take it out each time you fire it as a muzzleloader .
When i was shooting triple 7 I had to take out the firing pin and clean out the residue or my firing pin would stick and i couldn't get the action open. Hit up Mike Bellm for his firing pin and spring.
If you eliminate the blowback you will not have a problem with the firing pin or the spring. This is easily done with a small oring inserted in the breech plug for the primer to seat on.
Man and man's best friend still looking at the green side of sod.