I had the same problem when I shot flinchlocks. 3fg works fairly well. Another thing you can do (VERY CAREFULLY) is grind some in a mortar and pestle. I did it for years without a mishap, but I always used the following precautions: do very small batches - 1 tsp. max at a time, wear safety glasses and gloves, and keep the ground and unground powder separate and far (5 ft. or so) apart. If less than a tsp. of powder goes off, you'll get a snootfull of soot, some cinged hair, but no more. And, BTW, don't do it in the house, or you could leave a celibate life for a long time.