[Would you like to see this in-game?]
TL;DR: A KV-1S with an 85mm S-28 cannon.
The failed Object 238 was not the last 85mm KV-1S project. Around a year after the Object 238’s rejection, further development of 85mm tank guns was still underway. These guns needed to be compatible with both medium and heavy tank turrets. One of the ongoing developments was the 85mm S-53 cannon. The cannon was first tested in a stock T-34 (1943), however, it did not prove itself any more effective than the other 85mm cannons in development and did not pass trials. It entered a second set of trials in January and early February 1944. It passed trials this time and the order to put it into mass production was given. Before it reached production lines, however, the cannon had many of its issues ironed out and was redesignated as ZiS-S-53. The improved cannon was tested in April of 1944 and again had issues ironed out before finally being actually put into production. In August of 1944, a KV-1S arrived at the Leningrad ANIOP equipped with what was essentially a ZiS-S-53, however, as the mounting was different, the cannon was indexed as S-28. Unlike the Object 238, the mantlet of the KV-1S (S-28) was significantly altered as the cannon utilized the ZiS-S-53 mantlet. This mantlet was a perfect fit for the KV-1S’s turret and installation of it was relatively easy, which would allow KV-1Ss to be quickly rearmed with the new cannon had the project been successful. Trials of the KV-1S (S-28) took place from the 8th to the 20th of August. Trials provided overall positive results, however, there were complaints. The sight attached to the cannon had a small field of view, one of the turret ammunition racks broke during testing, and a maximum rate of fire of only 4-6rpm could be achieved. Despite the overall positive results, the KV-1S (S-28) remained a prototype as the KV-1S was reaching the end of its service life, being replaced with the IS-2, and the effectiveness of the vehicle was deemed inferior to the T-34-85.
Place In War Thunder:
The KV-1S is a fan favorite among lower-tier Russia players. Its decent mobility combined with its reliable armor and punchy cannon make for an incredibly formidable tank. Swapping an already punchy gun for an even more punchy gun with no noticeable loss to mobility would only make the tank better. Of course, a minimum reload of 10 seconds would most definitely make shot placement much more important. Playstyle would be a mix of the KV-85 and KV-1S. You have the mobility of the KV-1S with the stopping power of the KV-85. This would allow for a decently aggressive playstyle. Due to the cannon being in a KV-1S turret, you’d be able to utilize the diamond hull defense to its fullest as you wouldn’t have bulges on either side of your hull. Considering that this vehicle was a failed prototype, I think that the best implementation would be as either a premium or low battlepass reward. I lean more toward battlepass reward as battlepass vehicles are largely heavy modifications of vehicles we already have in-game.
Armament: 85mm S-28 cannon and 1x 7.62mm MG
Dimensions: 8.49m, 3.25m, 2.87m (L,W,H)
Armor: Same as KV-1S in-game.
Ammunition: APHE, APHEBC, APCR, HE
Side View:S-28 Side View:S-28 Rear-View:KV-1S (S-28) Turret Interior View: