Bofors shortages began with peacetime orders and factory tooling

Why was there a shortage of Bofors guns when wartime demand rose?

Factories had been tooled and supplied for peacetime orders, so scaling production to wartime quantities took time.

Peacetime tooling and order levels caused the shortage. Existing factories were prepared for the quantities ordered before the war. Wartime requirements rose far beyond that baseline, forcing tooling and production to expand. Peacetime capacity could therefore delay wartime rearmament even when the fleet already wanted the weapon.