Structural damage would
certainly be absorbed by the shields, and maybe even some of the kinetic energy (though I'm not sure on that one).
But what just comes to my mind, is that your
glorious "antimatter warhead"
won't detonate on shields - they aren't matter that it can react with... against them, antimatter
won't be any more effective then ordinary-matter mass drivers

. Which might be one of the reasons the Lucy's shields couldn't be downed in FS 1

.
Oh, and by the way - try my capship mod (if the download isn't removed already... in that case I'll have to re-upload sometime next week

) if you want to see Lucy-class shields in action. It's "only" on a Ravana there, but still strong enough by far

.
I'm sure it would weight many times the luci.
Huh? You're overdoing it a little bit here, aren't you? That bullet might be larger then a fighter, but certainly nowhere near a superdestroyer... it'd have to be of some really superdense material to outweigh those, for example like white dwarfs or neutron stars - and in the FS universe, it's certainly more likely that the Luci itself is made up of such material then something the GTVA put together...

@Send in the TMF:
Oooh, really?... Well - first, anyone can raise spawning numbers as high as he wishes. And second - you should see the original version of my supercap antifighter missile in action - something like 18*7 heatseekers per salvo... you DON'T want to be near when two or three of these salvoes go off

(and the numbers DO make sense there, as these are thought for supercaps defending themdelves in BoE-style missions... not that such missions would yet be supported by the engine, though).
Problem is, I don't yet have a PC that can handle this load with good framerates and without reducing the graphics quality to something pretty horrible

.
In what you said, even the biggest GTVA bomber really shouldn't be able to carry more then 1 of these, or, in the extreme, 2.
And against a Lucy or similar ships, it still won't do anything, since Helios' nearly don't do any damage to shields...
