It used to be the case in some countries; for example in my country the tobacco processing plants had the dual-purpose to build rifle ammo as most of the packin

It used to be the case in some countries; for example in my country the tobacco processing plants had the dual-purpose to build rifle ammo as most of the packing equipment used ~ 7.62 diameter. My cousin that worked in such a plant said it took less than 2 weeks for a full conversion. In this particular example there was no dormant capacity during peacetime, it was actively used on alternative production.