EMF company test fired this brand new gun with Pyrodex and sent it back to the owner via UPS Ground which took 4 days.
He called EMF and sent them several photos of the gun.
The person in charge contacted the gunsmith and he insisted he
cleaned the gun and it was in brand new condition.
Returned the gun, and EMF sent a new gun.
I have a few guns that had been left uncleaned for months in the dry Montana air with ZERO corrosion or rust after being fired with REAL black powder.
Just last night I cleaned a rifle that had been fired one shot, last November. I brushed out the ash from the rifle, a few patches later, her bore is as "smooth-as-glass"
Forgot about a Walker for several years under the seat of an abandoned car, totally exposed to the elements, with the window broken out. Two of the chambers had been fired, and there was zero rust. The 4 remaining cylinders still fired.
The orange Uberti lacquer had given up the fight, but the metal was just fine. A little sanding and tung oil had the weathered wooden grips looking better than they ever did.
I'm not just a traditionalist ranting...my first Pyrodex was in a cardboard can in the late 70's and I still buy a can from time to time and have a couple lbs on hand.
But the perchlorate used in Pyro is a real concern, and not just internet "lore"...
If you choose to use Pyrodex, then more power to you my friend.
But if you live on a road with an address, then you can shoot Real blackpowder, period!!