The percolates collect anywhere there is an edge, or groove, to hold it. It is much more aggressive than sulphuric acid produced by black powder. It also tends to create deeper pockets in more tightly focused areas. Any slight leakage in breech threads, or drum threads, or touch hole liner threads, are very susceptible to deep pockets that eventually cause failure. Your colonoscopy tool won’t do you a bit of good there.
The bore erosion will start as a light frosting, in the first two or three inches of the barrels breech, and will progress rapidly to a rough spot from there.
I quit taking in modern muzzleloaders for repair ( the unmentionable type on this forum) because all the owners wanted me to fix their guns so they could shoot all the substitutes without destroying their guns. There’s a reason that stuff is so much cheaper. If it worked just like BP, it would cost just like BP after all the manufacturers are’nt in it for the warm fuzzy feeling they get from selling their product cheap.
Hungry Horse