I don't fire caps or primers prior to loading for a hunt. My bore is dry and free of all oil or whatever else. I also ensure the fire channel is not obstructed. Therefore, no need to fire caps/primers.

I have heard that primer/cap fouling may absorb moisture from the air over time, so it may actually cause a mis-fire or hang-fire if you leave your gun loaded for a few days after firing caps/primers prior to loading.