「いい加減学んで下さい！ なのです。」　　建造して駆逐軽巡ばかり愛でてたら弾薬しか残らなかった！

"Start learning from your past mistakes already!" Since I love building destroyers and light cruisers so much only ammo was left!

He's probably using the 250 fuel, 30 ammo, 200 steel, 30 bauxite recipe, hence all the leftover ammo.