
The purpose of this thread is to discuss the high-end Soviet heavy tank IS-2, its historical aspects and how it is represented in game. While I understand that the game is currently in beta state and the stats aren't final, I still hope to influence the stat changes with this thread.
I'll try to break in multiple points the aspects of the ingame IS-2 that in my opinion are historically inaccurate.
1) The accuracy
Currently, the IS-2 has 30% accuracy in game which is unreasonably low. In reality, D-25T gun had a pretty low dispersion which was comparable to the German 88 L/71 even, this is very well illustrated in this article https://tankarchives.blogspot.com/2013/02/accuracy.html. At the range of 1900 meters, D-25T only had a dispersion of 120cm.
To illustrate, here's a 2.5m x 2m target (typical tank target) put over the D-25T dispersion at that range.

As you can see, all the shots are pretty much on target, so the dispersion isn't something that should result in low accuracy.
The sight used by IS-2 is the TSh-17 (4x magnification, 16° FoV) which has the same specs as the one used on the T-34-85 obr 44 (TSh-16). The only difference between those sights is the mounting and the crosshair scale adopted for different round ballistics, meanwhile T-34-85 has 45% accuracy with AP in game, while IS-2 only has 30%.
IS-2's accuracy tested in combat conditions was also quite good according to this article https://tankarchives.blogspot.com/2013/03/combat-accuracy-of-is-2.html.
My suggestion would be to bring IS-2s accuracy to 40-45% as there's no real reason for it to have such low accuracy. Moreover, low accuracy coupled with low RoF penalizes the IS-2 greatly in its gun capabilities.
2) DShK MG
Both IS-2s, obr 43 and obr 44 have DShKs mounted on the top turret. This isn't exactly historically accurate. According to Yuri Pasholok's article https://warspot.ru/12831-malaya-modernizatsiya-bolshogo-tanka IS-2s only started getting roof mounted DShK MG starting from November 1944 (USSR MoD statement to begin mounting DShK MGs on IS tanks was given in October 1944)
Further changes in the design of the vehicle were mostly insignificant, but in November there appeared a very significant innovation. On October 14, 1944, Stalin signed the decree of the State Defense Committee No. 623CC "On the installation of large-caliber anti-aircraft guns on the self-propelled artillery and IS tanks." In November, the first 25 IS-2 received anti-aircraft installations of DShK machine gun. For the first time, the anti-aircraft gun was tested at the beginning of 1944 on an experimental tank Object 244 (Object 237 with an 85-mm cannon D-5T-85BM), but that design was too cumbersome. The new installation came out much more successful and compact.
By the time IS tanks started getting DShK MGs, Operation Bagration was over.
3) AP/HE ratio
Current ratio of 8 AP rounds compared to 20 HE rounds feels way too low considering that the HE rounds don't seem to be very good (only 2 damage and 10% accuracy according to game stats). Soviet tank crew were taught to modify the combat load depending on who they were expecting to engage, considering that most of times we have tank vs tank engagements in game, I think it's better to give the IS-2 50/50 AP/HE ratio (14 AP/14 HE).
4) IS-2 obr. 44 armor
According to the game stats, IS-2 obr. 44 has 180mm frontal armor which is only a 20mm improvement over IS-2 obr. 43. I'm not exactly sure how the armor system works at the moment, but that armor increase is too low compared to what was historically done. Basically, the entire frontal hull was reworked: upper front piece was straightened and given either 100mm (cast hull) or 90mm thickness (welded hull), LFP was also thickened to 130mm. The 100mm UFP with cast hull was proven to be resistant to German 88 L/71 AP round at almost point blank distance, while the 90mm UFP with welded hull could not be penetrated from the distance of 300-400m. The one we have in game is the cast hull IS-2 obr. 44, looking at the model.
https://warspot-asset.s3.amazonaws.com/ ... b79f7a.jpg
https://warspot-asset.s3.amazonaws.com/ ... 052711.jpg
Make sure to check out Yuri Pasholok's article https://warspot.ru/12831-malaya-modernizatsiya-bolshogo-tanka which has a more detailed information on the matter.
It is worth noting, that IS-2 obr. 44 was the only serially produced allied tank that was capable of withstanding 88 L/71 at all combat ranges.
IMO, IS-2 '44 frontal armor should go up to 190-200mm.