I drilled the touch hole and had to file into the breech plug. It can ignite powder but will the groove be a problem for the patent breech? I don't feel like losing my face or fingers
There are many examples of a notched breech. That notch is too deep. It cuts through all the threads. You need at least 3 to 4 threads to seal the breech.
When you fire a rifle the gas created will take the path of least resistance. You have nothing sealing that breech plug. Stop and think what is behind that breech plug.
Only keep that one to duplicate the tang measurements on a new one so it sits down into the existing inlet, then toss it in the trash. Do not shoot with that one.
As already stated, with a patent breech, drill straight through into the anti chamber. No notching needed.