I'm not sure how the width will change anything much, unless the missile becomes ridiculously small.
Now, the Nova Cannon firing a shell at 5000 km/s, that's odd. Any idea of how heavy the slug was? Perhaps they didn't wait for the capacitors to be fully charged? Perhaps something was damaged. In Shadow Point (see my other thread), it was fired at near c, although it only fragmented a large asteroid while hitting dead center. As I said here, the asteroid itself, a Rok, is not a solid piece of rock, far from it.
Something of interest, quoted from here:
This makes a hell of a difference, and probably also solves the problem posed by the 1st edition quote as it required impossibly huge nuclear missiles.Khanaris wrote: As far as I am concerned, the 600 GT number is not "official", or at the very least is not representative of Gothic-scale torpedoes or firepower. It appears that the original reference is from the "Mission" book for the 1st Edition of Space Hulk. It mentioned that the Gothic Cruisers were carrying hundreds of Hellfire missiles that each contained 122 5 GT Warheads. This was from the 1st edition version, which explains why I didn't find it. The 2nd Edition version of the same mission mentions the same three ships, but the reference to their missiles was replaced with "fusion bombed down to a fine powder". So it is pretty much retconned by omission anyway.