Been shooting triple seven pellets for years and thought I would change it up. Just don’t want to spend 100 for knights upgrade with new bolt and plug. What kinda of blow back do you get with bh209?I have a Knight Disc Master Hunter. You will get alot of blowback if you shoot BH209 without upgrading the breech plug. You can minimize the crud ring by running a damp windex patch between shots and avoing using anything petroleum based in your cleaning regimen. Also try using a milder primer such as the Winchester T7 primer. These help to keep the crud ring at a minimum. I can usually get 4-5 shots off without having to worry about it.