I am using 90 grains of Pyrodex pushing a 250 grain Shockwave in my .50 cal Hawkens. Its a good load for my gun and works great. Might have been some damp powder like mentioned.

I used the same load in my other .50 cal thats an old inline using a no.11 cap So I started there with my new Hawkens. Results on paper are impressive at 50 yards with the Hawkens. Complete pass throughs with massive damage is all my older .50 cal left on deer. Hope its the same with my Hawkens this season.