Free: Contests & Raffles.
Bobs has them.I did that to mine. I cleaned my muzzy and put everything together loosely. Pulled the trigger and the hammer made contact with the nipple.
I won't be home until tomorrow but pretty sure i have a spare i could send you if you replace it when you find one.
When you find a source, buy two & keep a spare handy. Buddy had cracked nipple (you read that right!) one year when we met up at camp for opening weekend. The spare in my kit kept him from being sidelined all weekend.
Maybe worth a try?Red Hot #11 Muzzleloader Nipple - Knight Rifles https://share.google/DoZDYH79ZW1ijRAfJ