Just saw this post. Interesting. One of the many reasons we can't find what we need??? This article goes way beyond heave weapons. At the rate of ammo expenditures, companies will take years to make it up. War time economy rules.
A Lack of Machine Tools Is Holding Back Ammo Production, Army Says
The U.S. has enough raw materials, but the heavy equipment used to make artillery shells aren’t easy to buy.
www.defenseone.com