As stated the only difference is in using flint and frizzen for the spark istead of a cap.

I use 2F for the main charge in my double barrel 24ga (.577) flintlock fowler. I have primed the pan with 2F, 3F and ground up 3F to make it finer. No difference in performance for me. There were some tests done with a tuned Siler lock and 2F, 3F, and 4F powders to see what the lock time difference was. The difference had to be measured in hundreths of a second. The biggest difference is that 2F and 3F are "coated" to help reduce the rate at which they draw moisture. 4F is uncoated; therefore, it has a lower ignition temp. This makes it both easier to igite when dry but more likely to fizzle if the humidity is real high or it is raining. If your frizzen is throwgin nice white hot sparks you can use any granulation you like. If you are getting orange or reddish sparks go with finer granulations since they are not as hot.

Also you may wish to try your flint both bevel up and bevel down as your lock may throw better spark one way vice the other. Pad your flint with either leather or lead (some also use innertube though it is not traditional). Set the flint in the cock at half cock with the flint just short of touching the closed frizzen. Make sure the flint will bear evenly on the frizzen and will not contact the side of the barrel at rest or you could mar the barrel and shatter the flint.

Follow-through will be your best friend when shooting flinlocks. ALso wipe out the pan and wipe off the flint after each shot but be careful of the flint edge so you do not cut yourself. Powder fouling in the pan can turn to wet slidge real fast on humid days.

Some people load with the vent pick in the vent and other pick after loading but before priming. Try both and see what your gun likes.

When priming remember you want the powder below the flash hole. If the powder in the pan reaches the flash hole ignition will be slow as you have created a fuze. You want the prime to flash ans increase the number of sparks produced thus throughing a spark through the vent and into the main charge. 1/4 to 1/3 pan full works for most. Many also find that they get faster ignition bay tapping the powder to the outside of the pan after lowering the frizzen.

With careful loading ans application of a greasy waxy lube around the pan you can hunt and shoot in the rain. A leather cows knee provides additional insurance as does keeping the lock under your armpit.

Above all else remember to have fun.

These days my only "caplock" is a 209x50 Encore. My blackpowder guns are rocklocks; a Lyman GPR in .54 and a 20 bore Tulle Fusil de Chasse. I use 3f as the main charge for both and 4f in the pan. Nice thing about 4f is that a pound lasts all but forever. I ran a .50 caplock as a kid and if my memory serves getting a patched roundball to work is pretty much the same regardless the ignition system. Good hunting! McB