High explosives are even less regulated than firearms in the US. You can buy them by the ton and explosives are very inexpensive. This does not circumvent compliance with regulations for safe transport and storage, which is the practical limitation.
That... Wouldn't be tolerated if this was a 2nd amendment right. Imagine the same limitations applied to firearms.
People that buy high-explosives at scale just have some land outside of town where they can store them en masse. Problem solved. There are huge magazines of high-explosive just outside many major cities all over the US. Very infrequently, one of them goes “boom”, which kind of justifies forcing them to be on the outskirts.
You can own it, you just have to store it where it won’t wreck your neighbors if you are an idiot. Rural land is cheap.