Powder is not that hard to get and legal in small quantities most places since it’s used for so many things.
In a pinch you can get all the precursors fairly easily as long as you don’t order 2000kg of saltpetre like a dumbass (just pee on some straw and leave in the dark 6 months like a normal person), but actually making the stuff without a permit is illegal most places and while simple is still dangerous so probably don’t.
Well in Poland you are required to own a European Weapons Card to buy black powder as a private individual. To own it you only need to have a replica weapon spoken of earlier, otherwise it’s illegal. Also as you said manufacture of black powder is something well documented and materials are wildly available, but it is absolutely illegal to produce any explosive materials in Poland without a permit and can lead to prison time from six months to eight years.
