Stronger explosives tier 3 has 2 artillery damage bonuses, +30% and +40%, while stronger explosives 4 doesn't have any. Stronger explosives 5 then goes back to +50% like normal.
Assuming the 40% upgrade should be in tier 4 instead, plz fix :D
note: this typo is trivial and doesn't change anything in the end. Would be solved with better code (a loop that get missile bonus value and use it for shell ammo too)
