If someone other than your rifle manufacturer leads you to believe you need to Drill anything out to correct a misfire, I would certainly check with the Rifle manufacturer first because history has proven when you tamper with Weapons by altering their design you can be putting yourself in extreme danger and dont you agree that any alterations to your weapon especially when it involves machining procedures such as Drilling, should be performed by the manufacturer ONLY?
Personally,, I cannot believe anyone would tell you to "Drill" anything out on your weapon. Breech plugs are manufactured to perform within safe tolerances , anything you do by drilling to alter those tolerance puts you in danger.
Is every weapon owner who experiences a misfire expected to be a qualified machinist now?
What if you do decide to drill it on your own and from inexperience drilling you accidentally ream the hole too large causing your weapon to become unsafe? is Don ? or frontiergander or anyone else going to assume responsibility for your inability to drill properly?
Come on guys It doesn't take a lot of common sense here to understand that the idea of drilling is INSANE...
First Don suggested drilling, then he suggests CCI magnum primers, then he suggests switching to different bullets, what's he going to suggest next a new muzzleloader?
threeunder, I'm confident when I say I think you had "Contaminated Powder" and maybe I'm wrong but you tried new powder and had no issues afterwards.
If you have further concerns with your weapon, I SUGGEST you send it in to the manufacturer and let them handle it... That's the best advice I can offer you...
Good Luck...