Viet Nam can upgrade current S-300PMU-1 because its have available components from the S-400 Triumf, so that if they can be upgraded to the rules with a superior S-400 Triumph?
As you know, the S-400 Triumf missiles originally called the S-300PMU-3 because it shares a large amount of technology with the pre-S-300 variant include S-300PMU-1 and S -300PMU2.
The most significant thing is that the super S-400 Triumf covers much more than 40N6 ammunition, a 400 km shooting range, or a long-range 250-km 48N6E3 bullet rank, which also launched two 48N6E2 48N6E and large rounds.
In the same way, the next generation of S-300PMU-1/2 is also capable of firing 48N6E3 bullets although potentially carrying gamma-range precision limits a bit worse than the S-400, so when there are many common components, the base S-300PMU material-organize one from Vietnam can you upgrade the Triumf standard ?
It should be noted that in the S-300PMU-1 complex in Vietnam, we are using a component of the S-400 which is a radar that looks at all 96L6 instead of 64N6E Big Bird as a basic configuration. .
This has shown that the components of the S-300 and S-400 can work together, opening up great perspectives to improve combat skill S-300PMU-1 at S-400 or at least equivalent to S-300PMU-2 .
If it is going to be deployed, Vietnam could consider equipping its S-300 combination with long-range 48N6E2 / E3 interceptors, adding S-400 components or upgrading the package. Soft control to create synchronization between the gears, this is totally feasible.
However, one thing to note is that Russia is currently not prepared to supply modernization packages for the S-300 similar to the S-75 Volga (SA-2) or the S-125 Neva / Pechora (SA-3) because This weapon is not as far behind as the two.
Also, the most important reason to mention is that if the client intends to upgrade the S-300 to the S-400 level, it will directly affect the sales of the Triumph of Russia, while this is the Face Commodities.
In fact, Russia has not even sold 9M96 ammunition with the S-400 to its customers, despite the lack of it. The S-400 is unlikely to intercept low targets in flight to maintain the Pantsir-S1 market share and especially it is the S-350E Vityaz.
Therefore, the S-300PMU-1 long range air defense missile system in Vietnam is modernized and the S-400 Triumph is unlikely to happen in the near future.
The most feasible option now is to only complement its range of 48N6E2 interceptors with a range of up to 200 km.