I was pretty sure Lehigh was involved with the new Mountaineer breach plug design. He is likely involved with the Knight NFPJ conversion for the Extreme also. That should be a good indication that they will both be very BH209 friendly. It would be nice to know if the new ones use a vent liner too.

During the prototype testing before Knight was sold they had tested the "Slam" with BH209 also. It was a bare primer plug but had a powder pocket kinda like the FPJ plugs and a .037+ flash hole. According to TB that one also worked very well with BH209 but was dirtier with a larger flash hole. IIRC they made the hole smaller in the last version and it worked much better.

I am curious how much different the new bolt is vs the one on the Slam prototype. That one looked pretty cool.