No, IS-4, IS-4M, T-10, and T-10M were all real. Not all were put into production though.

Whilst the IS-4 is real, it was never fitted with the M62-T2 Andrew was talking about putting on his kit of the tank, hence is a what if.

exactly. this was new gun and barrel introduced on T-10M since 1957

When the IS-4 was being considered for upgrade to the IS-4M, several upgraded armaments were considered/looked at. The M-62-T2 was considered. So were other main guns. Ultimately the IS-4M project was not pursued so it is a "paper-panzer" in that regard: there were no prototypes that carried the gun. But, the IS-4 could have very easily had the gun installed, there was no physical reason it would not have worked...the IS4's problems were beyond its main gun. Hence it remained relegated to exile duty in the far east facing China until the last units were officially decommissioned in 1992 I believe. There are paper-panzers that are true fantasy, and then there are paper-panzers that were practical, but unbuilt. Maybe it is splitting hairs. Steven Zaloga just did a nice research piece on the IS-4 in the most recent Boresight (AMPS) magazine and the tank has a very convoluted history.

Alright, with a bit of research and sleep... IS-4 did become IS-4M, but it was a small improvement involving side skirts, transmission tweaks, etc.... Major points in the development of the IS-4: 1. Kotin, a rival chief designer, hated the Obiekt 701. Rivalries in Soviet tank design had some good points and bad points, but in this case the IS-4 was always dogged by Kotin messing with it. 2. In 1950 the IS-4 was rushed to the Far East Military District to counter UN forces in Korea (there was worry of a UN invasion in the Soviet Union or Manchuria). With first hand experience of Soviet equipment (albeit in the hands of the North Koreans and Chinese Volunteers) there was worry about Soviet tank design and the aging D-25T gun was considered to be replaced by several other guns in development. Rearming the IS-4 was considered to be cost ineffective and unnecessary considering the development of the T-54, and the development of what would become the T-10 tank. 3. Deteriorating relations with the Chinese lead to the transfer of 80 IS-4M tanks to the Transbaikal region in 1967. Once again there were thoughts to rearm the IS-4M, this time with the M-62T2 gun currently in use on the T-10M. It was considered unnecessary especially with the combat debut of the BM-21. 4. All remaining IS-2M, IS-3M, IS-4M, and T-10M tanks were officially removed from service in 1997 by order. I hope that helps clear it up a bit. Yes, no IS-4 tank had the M-62 gun installed. It would be a "fantasy tank" in that regard, BUT it was considered and feasible. Take it for what it is worth.

Ooooops, wow didn't mean to set the cat amongst the pigeons here . Thanks for your effort as always Jacques

It was Cookie Sewell, not Steve Zaloga. KL

Kurt is correct. Sorry to "Cookie". Dang it all...well, it keeps me humble. And it is not so much a flurry of excitement as a good learning opportunity, especially when there is a lot of "creative enhancement" in games like WoT. What could have worked, what never would have worked, what was actually tried. The S51, for example, was tried and would not have worked (at least not in the form they tested and NOT the way it is in WoT). But if we don't have the discussion, we do not get to learn all this cool stuff. Besides, it also gives more use to the Aber gun.

Thanks Roman for the nice report on this. Aber makes some very detailed stuff! Jeff