I have kept mine loaded for days during the hunting season. I get them cold in the garage before loading, and keep them cold until something expires. Don't warm them up in the house or the cab of the truck. Condensation is a killjoy. SW
Condensation should be a major concern for sure. Other than condensation and/or perhaps being out in rain or snow, there is no need in firing a ML at the end of a day. This is especially true if one is going to be going back out the next day or so. Black powder will torch off just fine if it hasn't gotten wet.
To prove a point here, I once left one of my ML loaded from the end of one season until the opening of the next years season. This was in TN, a high humid state. I kept the ML hanging over my fireplace. I put nothing over the muzzle nor the nipple. Also, I lived in a block house, which always seemed to hold humidity more. Before season the next year, I put a cap on the ML, stepped out the back door and it fired just like it ought to.
So indeed, a sub powder might be questionable but as long as black powder is kept dry, it will fire.
To add to this, here in KY I have been out in light rain for up to 6 hours with my Crockett squirrel rifle, and several more times since. It fired just fine at the end of the day. I had nothing over the muzzle nor the cap, other than let the hammer all the way down against the cap to help keep moisture off of it.
Before I came to the conclusion that there is no need to fire the ML at the end of each hunt, after I moved back out west, during some elk hunts I would go about 4 days before firing my ML just to make sure. I traveled and hiked many miles during those days and not once was there an issue with my ML firing.
If there's going to be an issue, it would be due to how well the ML was cleaned and cleared prior to loading, or a bad cap. It won't be with the black powder.
