Dave,
Yeah when I line it all up, the edge of the pan nearest to the frizzen is right on that flat. Where I to drill the vent centered in the pan, I'm well behind that.
From what I've been shown, Naragansett Ferguson's, using TRS parts, had their breech screws notched to fix this problem. The parts are so expensive If hate to botch it.
The whole barrel is inlet, so I don't think I can move the breech back, sliding the barrel back and aligning the chamber with the lock inlet. That left me with the bright idea of altering the lock inlet.
I will call them. Id love them to make it right, but I'm afraid the wait time it takes to get a new one would kill me!
Greg