I have two I love them both, they are very accurate easy to clean and just feel good. They are picky about which Sabots to use and I have to use harvester sabots with both I shoot 240gr XTP bullets and 90grof 777 powder. They both shoot around an inch at 100 yards
A new plug needs to be "mated" to the barrel. They offer a cheap installation tool for this. The tool just needs to be used one time to tighten the plug down really tight. After its been used once you should be good to go.
Being that BH209 is the most difficult BP & Sub to ignite (i.e. the shorter flame channel breech plug - which is no problem) I can't help but wonder why they just don't supply the gun with the newer Brecch Plug - $$$ I guess.