Yooper
I shoot 110 grains of T7-2f and i do also get the primer spearating from the battery cup on occasion. It does not always happen. I expect the same thing to happen with BH-209 but more often because BH-209 burns longer than than T7. I would think it would be important to have a weather shield installed - "just in case" to keep everything inside.
I have made two different types of weather shield - one from a simple 12 gauge shot shell and the other from a copper pipe fitting. The copper one needles to say is the stronger and miht be what you wan to use while shooting BH-209.
Here is a picure of both although the copper one shown if for a A&H.
