deer655
Please.....Do not continue using BH209 in that gun. BH when ignited, produces MORE(greater Volume) of actual GAS, than any other black powder sub on the market. And that's because it's acts very much like smokeless powder.
These hot gases must go somewhere, so most of it goes out the barrel pushing the bullet. HOWEVER, this will increase the blowback gas pressure going back towards the breech plug, and shoot out rearward,
thru the flame channel toward the spent primer. It can/will blow past the primer and hit your face/lower mouth-chin area. This increased blowback can blow your old primer into peices. These peices can become projectiles and have the ability to cause some serious wounds.[:-][:'(][

]
Please heed
cayugad's advice, and just stick to the regular powders and subs. They are more like burning expanding solids, and will have a greatly reduced blowback effects