I'm not so sure a long barrel is all that important for black powder Ron. As an explosive, it burns up pretty fast. I really don't know if it continues to build pressure as the projectile travels down the bore.

I do know I conducted a velocity study in the short barrel of my X7 with GOEX FFFg and got continuous velocity increase as the charge was increased.



I've chronographed only one load with T7 in the X7. But as you can see, it beat all heck out of GOEX. I still use GOEX though for my 175 yard or less hunting situation because the trajectory is flat enough for me and accuracy is just fine.