>>508042630>TL;DR: maybe that bomb works at the dept specified on a flat surface if dropped at a 90 degree angle. The bunker is in a mountain, which is anything but flat.Since most of your enemies will be covered by metal or sand or granite, use the old chemistry.
I heard GREEK FIRE (tar mixed with sulfur, then rolled in lye, and dry limestone dust plus more sulfur dust, then rolled in hot tar to cool into a stable ball) can destroy limestone and make it burn like wood.
When using Greek Fire in a boat, stab the ball with an awl, insert a short wick rope, light wick, toss into water. Ball reacts with water to rapidly heat up, wick provides ignition source, tarry goo floats on water.
Otherwise, now for a Bunker Buster Bomb, a similar chemical reaction could be simulated with a plasma torch. Core of bunker buster is a basic plasma torch, push sulfur powder mixed with hydrogen peroxide (20% or higher), plasma cutter jets a crazy hot sulfuric acid jet into attacked surface. You'd have to cover exposed reactive surfaces with a fluoride crystal high melting point alloy though. The plasma reaction is best achieved by electronics, after you've superheated the sulfur-peroxide mix (piranha solution jet at 9000 degrees) it becomes a pool of hot superacid death. If you ignite thermite before the fluoride crystal layer evaporates, that basically becomes a bomb once it hits anyplace colder than itself.
Ever see thermite reacting inside a frozen ice block?
Mythbusters - Thermite Vs. Ice
https://m.youtube.com/watch?v=w6cMmk8LZgQ
It's essentially a reaction producing a lot of hot gases sinking into materials too hard to release those gases effectively, too much pressure trapped with too tiny a hole to vent and you get a big badda boom.
