One thing about Russia is that they dont think about things the same way we do in the West.
They are a very primitive people with a childish mentality (which I say cringingly as an American with Finnish heritage), and small arms development weighs heavily in the government's credibility to its serf army.
Take how impossible it is to explain the complexity and capability gap in the different weapons systems in the US inventory even to its own servicemen, let alone civilian gun enthusiasts in an open information society, then amplify that by a huge factor for poverty-stricken peasants who have never really understood the major improvements of the stages of industrial revolutions over the past few centuries.
Their language gives you some insight into what Im talking about.
Any vehicle in common daily vernacular is referred to as machina" and its effectiveness is measured in rabota (it works?).
Because of the northern latitudes of the bulk of Russian population in what equates to Hudson Bay in Canada, its brutally-cold most of the year, land-locked, far away from the trade routes. Things move slowly, so the major inputs of the Industrial Revolutions have not caught on there fully....ever.
Small arms represent a symbol of military might that a serf can understand, regardless of how effective they are in an overall weapons mix.
In practice, the Russian military has been focused on artillery since the late 1800s arms race after the Franco-Prussian War, where German high-strength steel cannon tubes allowed them to crush the French, even though the French had better rifles.
Within the Russian military and culture, the Kalashnikov is the symbol of their superiority. They truly believe its the best firearms design in the world and no amount of logic, reasoning, or dispassionate analyses can convince then otherwise.
That symbol then serves as a template for the rest of their weapons. If the peoples designers got it so correct with the Kalashnikov, then of course the respective engineers got it right with the MiGs, Sukhois, tanks, artillery, etc.
Maybe this new cartridge is an effort to continue that concept, as some of their more clever gun guys have lamented on their forums, Why did we not do a 6.5x39?
They also watched the Chinese develop the 5.8x42 High Performance Intermediate Rifle Cartridge with no real response from Russian designers until now.
This appears to be more like the Chicom 5.8x42.
----------------------------5.8x42---------------- 5.45x39-------- 7.62x39------- 5.56x45---------------- 6.5 Grendel