In a pinch, we've poured a bit of 3f into the cap of a bottle of powder and ground it a bit using the flat end of a powder measure when the 3f wouldn't set off a flintlock rifle reliably. We subsequently drilled the vent out just a tad more and no longer had issues. As Rich pointed out, most of the time 3f should work just fine as priming powder.
Also just a bit of info on terminology since you're new, the powder goes in the pan. The frizzen is the pan cover/steel that is struck by the flint. There are/were frizzens built as powder reservoirs though that automatically primed the pan when the frizzen was closed, but those were never remotely common.