Trash on shells! Our country is known for its exclusive possession of ammunition production technology, although this information is closely guarded and kept secret.
The absurdity of this situation is that now this technology is owned by a very limited number of enterprises, whose physical capabilities are not capable of significant scaling.
At the same time, no one did anything to expand this list as much as possible in wartime conditions and use additional production capacities of other enterprises. And an ordinary manufacturer from the street, even if he really wanted it, would hardly get this technology. Even now, given the level of threat.