I hate to drag out a beaten cat, but I found it interesting that apranently a French Oceanograhpy ship using a towed sonar mapping device detected a large "man made mass" roughly near were the U.S. claims the Musashi was sunk in the Visayan Sea area.
What is familiar about these circumstances is that this is how most shipwrecks are found in the past 20 years it seems, as blips on bottom scanning equiptment.
No dive was attempted as wreck exploring was not the reason the Researchers were out there.
Just food for thought.
As for the ammunition concerns, upon researching Musashi's twin sister in her state, various shell and ordance litter her resting place, yet explorers have combed her remains for documentation and retrieval of artifacts for the Yamato's various muesum exhibits.
I suppose it all comes down to what happend on the Musashi's ammunition storage compartments and mixing of charges propellants, and shells as they rattled around the inside of the ship as she went down.
Also even where exactly they were stored and her interior ammuntion bulkheads remain a mystery as almost all prints of both her and her sister were lost with history.
"This conjunction of an immense military establishment and a large arms industry is new in the American experience"- Dwight D. Eisenhower , Jan 17,1961.