outdoorsmen
I did read your other post and at the time I was reading it I thought I might interject a thought - but I didn't so I make a suggestion now. BH-209 is a smokless progressive burning powder. It requires a good pressure seal on both ends of the barrel to burn correctly. Without the seal it will not ignite and progressivly burn - in fact it might even quit burning. The better the seal the better the burn. As I remember you indicated the bullets you were using went down the barrel relatively easy... that might be the reason you were getting the hang fires.
Try a tighter fitting sabot/bullet combination and see if your problem continues. I have a Knight ELite with a MH barrel and the same breech plug you are talking about - it seems to shoot the BH-209 just fine. Although right now I do not plan to make the switch to BH - I will continue with T7