lefteye

I use powerbelts in a flintlock and an inline. 70 grains of 3F puts a 295 through deer. I use 100 grains in the inline with a 245 powerbelt and it is awesome out to 150 yards.
If you shoot any distance use a heavier bullet. They retain energy better even if the drop faster. Practice will tell what to allow. I get good groups at 100 yds with the 348 grain powerbelts but have not tried one on a deer yet.
If you put a .50 hole through both lungs expansion is not really a factor.