I just converted my knight mk85 to shoot 209 primers so I could start using blackhorn 209 powder which my brother was highly recommending.I started out with 100 gr equivalent and a precision 300 gr bullet. Every time I shot was would feel a hot flash across my forehead. After cleaning the gun I believe what I was feeling was breech plug grease maybe blowing out. When I used triple 7 this would never occur, although I was using powerbelts with the triple 7. I was extremely accurate with the blackhorn but I'm kind of worried that my gun may not be capable of shooting this load safely.I loved being able to shot without swabbing between shots but was disapointed at how hard it was to clean up compared to triple seven. Somehow my trigger assy was filthy. Again the only way this could happen would be for the shot to be venting thru my breech plug threads, if not I cant see where else it would be coming from.