I have not yet purchased Space Age DLC, so I cannot personally test them with asteroids.
But this seems to be a common issue introduced by the game, as I have seen others reporting this issue in a few weapon mods and in official forum.
So I guess we have to wait for Wube devs to deal with this, as it is not specific to this mod or Schall Tank Platoon.
P.S.: At least the "75mm" caliber cannon shell series are purely unmodified (except for name changes.) If those shells do not work, it is vanilla issue/bug.
The 88mm and 128mm cannon shells are just damage scaled up versions of vanilla ones, without any "black magic" in them.
