alt Hacker NewsExplosives are a weird case because Americans can just buy industrially manufactured high explosives. Attempting to DIY an explosive that is almost certainly inferior to what you can buy commercially is a red flag.
Before 9/11 caused them to tighten up the rules, buying high explosives in the US was cash-and-carry. You could walk in and select different kinds of high explosives from a giant menu. If you wanted something unusual they could special order it. The only real requirement was that you had a non-sparking container for it (basically, no exposed metal) when you carried it away. Most people aren't familiar with this because most regions of the US don't have much need for these types of stores.
It still isn't difficult today from my understanding, there is just more paperwork. The more practical hurdle is complying with safe storage regulations since they want some distance between where you store it and the neighbors. You can't just stash a few hundred pounds in your suburban garage.
>before 9/11 caused them to tighten up the rules,
You mean "before the Weather Underground blew up a bunch of random shit with hardware store dynamite in the 1970s".
>It still isn't difficult today from my understanding, there is just more paperwork.
The paperwork and compliance is enough of an expensive PITA it precludes everyone who isn't a regular commercial user, which is exactly the point.
It used to be that farmers just cleared forest and blew stumps and rocks up. This might sound absurd but when you start looking at the cost of doing that job with equipment it's preferable if you're rural enough to not endanger anything.