I have the tool and always remove the FP assy from the bolt.
You never mentioned if those were reenactment caps.
#11s work great, if you buy the magnum caps. #11 nipples have good options too. You can buy Red-Hot or Spitfire nipples, which are hotter.
Another thing I recommend is using FFF powder, not FF... and real blackpowder or 777. Pyrodex accepts moisture faster than the other two powders I mentioned.
Lastly, don't let that loaded barrel change temperatures drastically. No warm to cold. No cold to warm, then back out in the cold.