For those who don't know, black gunpowder is some FUNKY stuff.
First, it makes scads of fouling, which is hygroscopic-it draws and holds water. This means the gun must be cleaned every time it's used, and several days thereafter.
Second, it's pretty powerful stuff, you can make a jim- dandy bomb with it.
Third, it's liable to become more powerful and more sensitive with time-some archeologists at a Civil War battlefield departed skyward unexpectedly when they passed a metal detector over a very large mortar shell about a century old.
The Dupont fortune was founded on their powder mill.
Finally, guncotton(nitrocellulose) is so easy to make, it was first made by accident. But I'm not going to tell you how, just as I won't reveal the one step that keeps home made nitroglycerine stable.
It's not good to know.