I just added links for 2 BP's that are capable of producing the ammo. One is a Level 3 Base that has a Small Constructor, the other is a level 5 HV Production Cube, with the mobile constructor. You are correct that the SV constructor uses cobalt. The other two options I linked do not require cobalt.

Ok i look in game and HV Constructor dont need Cobalt in RE but SV Constructor need Cobalt. So you need an mini HV Construtor working first

That’s not true. They only require basic resources only. No cobalt is needed.

But HV/SV constructor need kobalt.

Just checked and you're correct! Sorry about that :) ... Small constructor or HV/SV constructor work for the ammo.

The mobile constructor for HV/SV, and the small constructor for base/CV will produce the ammo. All of those are also available by level 5 to make the ammo needed.

Very cool design and seems quite handy. Not too early-game though, as you need a large constructor to make the ammo, if I'm not mistaken.