"...arms makers aim not to get burned again..."
[[[Were I the owner of an ammunition company, my factory would have an additional shift added and be running 24 x 7 x 365 to capitalize on immediate market demand.]]]
They all are now. Three shifts, 24/7. Its basically war production.
They are actually having trouble obtaining raw materials like lead, brass, etc.
To add a whole new line costs up to a million dollars or more for machinery and infrastructure alone. Then you have to train people to run it all. Then when demand drops you lose a ton of money to mothball an entire line/building. Only two companies in the world make ammo manufacturing machinery.
Demand is TEN FOLD what it was in 2018 where a billion rounds of ammo were made that year.