Slasher wrote:But without the protons and electrons to generate the electrical fields that pull the mass together, wouldn't neutronium also essentialy be like a liquid, without any kind of structure, as its just a dense mass of neutrons with nothing to hold it together...
Neutronium (assuming we mean "degenerate neutron matter") rounds are not pure neutronium - if they were, one round would mass more than the entire ship.
One cubic inch is roughly one billion metric tons.
I assume that there's a small amount of neutronium, and the rest is some sort of containment system to keep it from asploding, as others have mentioned.
Also, with respect to Mecron, other than gravitational binding, the tensile properties of degenerate neutron matter are not well understood. "Incredibly dense fluid" is the most common model I've seen.
Of course, in SOTS, neutronium may not be degenerate neutron matter.