CVA OEM plugs work perfect without modification to the flash hole or channel. Proper head space adjustment is more important than a dished out plug face.

With my new Optima i had zero trouble firing BH209 with just my head space adjusted. Many many members on my forum run the head space adjustment on a factory plug since i taught them how to do it. I still prefer the 5/32" flash channel as i am mainly a target shooter and the dirtiness doesnt affect the group size as it used to on the factory 3mm flash channel.