What is the difference between the S-300VM and the S-400?
I read somewhere that the the S-400 was offered.
Genesis of the Antey S-300V/SA-12A/B Gladiator/Giant
While Antey's impressive S-300V family of SAM systems shares its earliest conceptual origins with the Almaz S-300P family, the two product lines diverged dramatically very early in their development histories. As a result, they share the same technology base but are essentially unique designs, optimised respectively for the needs of the prime customers, the V-PVO and PVO-SV.
While the PVO-SV shared some static and semi-mobile radar systems with the V-PVO during the early 1960s, the PVO-SV deployed its own unique inventory of fully mobile SAM systems, reflecting its role of providing air defence cover for highly mobile Soviet tank and motorised infantry divisions. By the end of the 1960s the PVO-SV had deployed a three tier system, with the cumbersome ramjet powered command link guided 2K11/3M8 Krug / 1S12 Long Track / 1S32 Pat Hand / SA-4 Ganef system providing long range area defence, the quite effective 2K12/3M9 Kub / 1S91 Straight Flush / SA-6 Gainful system providing medium range area defence and the 9K33 Osa / 9K33 Romb / SA-8 Gecko, 9K31 Strela 1 / SA-9 Gaskin, and ubiquitous ZSU-23-4P SPAAG providing low altitude point defence.
With the exception of the large 3M8/SA-4 Ganef this package was widely exported in the Arab world and Africa and whilst achieving some initial success against the Israelis in 1973 generally suffered greviously when applied against Western air power and electronic combat forces. By the early 1970s it was clear that a new generation of systems would be needed to challenge growing Western SEAD and EW capabilities. The S-300V system was to provide the top tier in the new air defence umbrella, directly replacing the 2K11/3M8 Krug / 1S12 Long Track / 1S32 Pat Hand / SA-4 Ganef system.
Unlike first generation PVO-SV 3M8/SA-4 Ganef the S-300V would have a much broader role, encompassing both long range / high altitude air defence but also defence against US tactical ballistic missiles, specifically the Lance and high performance Pershing I/II, the FB-111A's supersonic AGM-69A SRAM standoff missile, and the new US Air Force MGM-109 Ground Launched Cruise Missile - a trailer launched nuclear armed Tomahawk variant based in the UK and Western Europe. As a result the S-300V would have to provide exceptionally good detection and tracking performance against low radar cross section targets, at very high and very low altitudes, while retaining the very high offroad mobility so typical of established PVO-SV tracked area defence SAM systems, and possessing exceptional resistance to the much feared USAF EF-111A Raven tactical jammer force.
The S-300V was the result of these pressures - an expensive, complex but highly capable dual role SAM/ABM system which remains without equivalent to this day. It was to be an “Army level” or “Corp level” asset, protecting the centre of gravity of the Red Army's mechanised land forces against attack by nuclear and conventionally armed systems.
The S-300V was supplanted by the enhanced S-300VM during the 1990s, using the 9S15M2/MT2E/MV2E, 9S19ME, 9S32ME and 9S457ME components, and improved 9M82M and 9M83M missiles. This system has been marketed as the “Antey 2500”, intended to highlight its capability to engage 2,500 km range IRBMs with re-entry velocities around 4.5 km/sec. The 9M82M has double the range of the 9M82 against aerial targets, at 108 nautical miles, and increased terminal phase agility - a single shot kill probability of 98% is claimed against ballistic targets. The S-300VMK is a proposed wheeled configuration of the design, using a BAZ 69096 10 x 10 all terrain truck chassis.
Provisional data - Russian sources.
S-300VM Kinematic Envelopes (Antey)
@vostok @ptd3 can clarify more regarding S-300 variant .