Also, in the future, let's respond in kind:
Future Design: CS1-I "Terror" Incendiary Shells
Our mathematicians have thought: What if you could easily make fire without magic? After intense sessions of study and design, they've come up with a solution: Incendiary rounds.
The new shell foregoes our usual flaw of a dependence on magic. Simply load the shell into an HCx-E and fire!
As the shell approaches its target, one of two things will happen: The impact will trigger a simplistic ignition mechanism inside the shell and it'll disperse a payload of flaming oil, showing throws filthy Moskurgians how to properly use fire.
Or, if the shell hits an active magic field such as a wizard casting a spell, small crystals based off of the design of the Anti-magic bomb will break up, in doing so igniting the payload. The range of the anti-magic crystals ensures that the shells won't disperse too soon. Once this happens, huge swaths of land will be engulfed by fire coming down from the sky.
Future Revision/Design: CS1-E "Annihilator" Explosive Shells
After finishing the concept for the CS1-I, our mathematicians decided to say "screw it" and make a shell reliant on magic. Consequently, this was a simpler design. What if instead of relying on enemy magic to trigger anti-magic crystals, we trigger it ourselves?
"Charging" the crystals is a simple process easily taught to even apprentices failing in the Academy. The mage travels a regulated amount of energy into the crystal. Once this happens, the crystal becomes unstable and is essentially a ticking time bomb, though impacts reliably trigger the crystal as well.
After the crystal is triggered - either through time or impact - it'll releas a huge explosion dwarfing the Anti-magic bomb. The magical energy in the shell is mathematically optimized to all release at once in this devastating explosion rivaling a fireball.
(CS: Cannon Shell)