Is it that they can't work, or that they are too expensive for Russia to field any appreciable amount that won't just make them valuable targets? Its not trivial to produce the hundreds of thousands of rounds you need for each one to be ready.
If there is any nation on earth that is capable of cheaply producing large quantities of simple weapons of war it is the Russians. The issue is not a lack of cheap bullets.
If there is any nation on earth that is capable of cheaply producing large quantities of simple weapons of war it is the Russians. The issue is not a lack of cheap bullets.