I like and use Meal D from Goex which is black powder flour. Actually though if you use Goex in any grade all you have to do is sieve out the fines and you will have all the priming powder you will ever need for free. Grain size does regulate burn rate in confinement and smaller grains are easier to light so there is some speed benefit for target work in my opinion.So I have always used the same FFFG powder that load my flintlock rifle with to prime the pan... I know most people use FFFFG for priming and it supposed to give a faster ignition than just using 3f like I always have. So today I crushed up a very small (safe) amount and filled my primining tool. Has anyone tried this before? It seems a waste to me to buy a different granule size powder to prime with and what I crushed up is smaller than 4f and more of a powder. (Before anyone jumps in to say this is unsafe, I only crushed 10 grains at a time and wore welding gloves and a face shield while doing so).