No they are Traditions flintlock rifles. I would guess that their preference for the finer powder is related to their patent breech design and the way fouling accumulates perhaps blocking all but the finest granules from fully filling the firing chamber. The two rifles I mentioned will work well with 3f for the first few shots but after that I get a lot of pan flashes if I don't switch to 4f.
I generally shoot 20-30 shots at a session and don't do any swabbing between shots. I do pick the vent hole before every shot to make sure it's clear.
I have two other Traditions flintlock rifles with the same patent breech design and I thought they both worked well with 3f as charge, but looking through my records the Hawken had 37 flashes out of 521 shots for 7% failure and the Deerhunter had 40 flashes out of 399 shots for 10% failure. I'd be willing to bet they'd both do better with 4f charges.
With all this in mind I'd be happy if I could grind my powder so that I'd yield as much 4f as possible. I did a little experimentation yesterday by taking some of the 3f I already had made and running it through my grinder on it's finest setting. I ended up with about 50% of the 3f turned into 4f and 50% into fines. That's more fines than I'd like to have to reprocess but maybe that's as good as it's going to get. The next time I make a fresh batch of powder I'll play with the settings on both the mill and the grinder to see if I can get more 4f without too many fines.
While I'm talking about reprocessing fines I have another question for you guys. I've noticed that when I reprocess my fines I get harder pucks than those that are made from fresh meal. This is just a seat of the pants observation, I'll have to check some weight to volume samples to say for sure. Another project for this winter. Has anyone else noticed or verified this? To my mind the reprocessed fines have been run through the press twice so it could make sense if they are more dense. But I will need to check this out more.