Suit yourself. It is your investment. Do as you wish. But...........Just for discussion.......just for fun.............
What is the risk? Blackhorn powder is not hygroscopic. Blackhorn burnt residue is hygroscopic. Blackhorn powder isn't hygroscopic.
If the gun hasn't been fired, there is no risk is there? Or is there? What is the risk?
The problem that I have with leaving muzzleloading firearms loaded is that regardless of how one tags/identifies the loaded gun; it's always possible to lose the tag/forget that it was left loaded. And, the possible negative consequences of that.
Leaving a weapon loaded overnight while on a hunt is one thing. There is is certain situational awareness regarding the loaded weapon vis-a-vis the hunting camp/cabin. Even for the duration of a multi-day hunt in the above situation.
But, for long hunting seasons, overlapping seasons, or consecutive seasons interupted by gaps; where the hunter is unsuccessful early in the season, and wishes to leave his/her weapon loaded for months at a time, at home----- NO THANKS!!!!
I don't live in the 18th or 19th Century where my life, and my family's life depends upon a constantly loaded muzzleloading firearm to protect ourselves from maurading Indians, outlaws, bandits, or foreign armies.
Neither, am I dependant upon a muzzleloader for feeding myself, or my family; where a readily loaded gun might mean the difference between eating, or going hungry.
I live in the 21st Century, and even though BH209 is non-corrosive, I still see no compelling reason to leave my m-l weapons loaded for long periods of time.
When I leave the range, they will be empty. When I am finished hunting, I will pull the charge, or shoot the weapon dry.
For self-defense I'll take a .45ACP 1911, a pump-action, 12 gauge tactical shotgun, a 6.5 Creedmoor, bolt-action Steyr Scout rifle, and a 6.5 Creedmoor, AR-10, semi-auto rifle. NOT ONE OF MY MUZZLELOADERS.