““Black powder?” LOL!”
Black powder is a serious explosive. But 200 lbs of it would cost probably close to two grand. And buying it anyplace in that quantity would draw serious attention unless you are a club firing replica guns, civil war reinactors, etc.
The guy must have watched the explosion scene from the movie “What About Bob”.
I reload all my own cartridges. I typically buy 8 pound containers of my favorite types of smokeless powders to save money. Pistol cartridges use only a few grains of powder a piece. There are 7000 grains in a pound. So eight pounds of my favorite, Hodgdon Titegroup goes a long way. Shotgun and rifle cartridges use a lot more powder per cartridge, but 8 pounds is still enough to load a heck of a lot of them. I don't remember ever buying more than two or three 8 pound kegs at a time... these days even that amount be enough to earn a little unwanted attention.
In the 60s my dad and grandfather used dynamite a lot to loosen big stumps when they were clearing land. I remember the first time they tried ANFO; they didn't pay close enough attention to the instructions that they were given. They had a large stubborn stump, there first couple of tries didn't go so well, so they used more than what was recommended. It was a big explosion and the stump went a long way into the air and came down on the hood of my grandfather's old pickup truck and smooshed it real good. He was very upset.