The effective ranges to combat our existing heavy tanks at least would make it survivable. If Hitech modeled the blast force of the HE round per the wiki info below, it would be a danger to lesser tanks in the stable with a single shot at 1500m and closer. It would probably get used like the Tiger2 mostly for local base defense to reduce the real probability of the panther and T34\85 using their speed to out maneuver it. It would be a bomb magnet on par with the Tiger2 but, in our current MA environment, it could compete while the short magazine would be it's greatest sore point for players. Who wants to get off a spawn, drive two miles to setup a hide, then run out of ammo in the blink of an eye per our MA environment play style? Still, the destructive dominance of the 122mm round against the stable and buildings would be worth listening to the whines on VOX and 200.
From wiki:
https://en.wikipedia.org/wiki/IS-1_and_IS-2According to the same Wa Pruef 1 report, it was estimated that at 30 degree obliquity the hull armor of the Soviet IS-2 model 1943 would be defeated by Tiger I between 100 and 300 m (0.062 and 0.186 mi) at the driver's front plate and nose,[14] while the IS-2's 122 mm gun would penetrate the Tiger's front armor from between 500 and 1,500 m (0.31 and 0.93 mi).[14] A Panther had to close to 600 m (660 yd) to guarantee penetration of the IS-2's frontal armor (The Panther's 75 mm gun could penetrate the IS-2 model 1943's mantlet from 400 m (440 yd), front turret from 800 m (870 yd), and driver's front plate from 600 m (660 yd)[15]), while the IS-2 could penetrate the Panther at ranges of 1,000 m (1,100 yd).[16][Notes 1] However, in the summer of 1944, the Germans experienced a shortage of manganese and had to switch to using high-carbon steel alloyed with nickel, which made armor very brittle, especially at the seam welds. The performance of the 122 mm AP shells of the IS-2 against the Panther improved considerably. The reports from the front described cases where the BR-471 APHE round 122 mm projectile fired from 2,500 m (2,700 yd) ricocheted off the front armor of a Panther, leaving huge breaches to it.[17][unreliable source?] According to Steven Zaloga, the IS-2[16] and Tiger I could knock each other out in normal combat distances below 1,000 m (1,100 yd). At any range, the performance of each tank against each other was dependent on the crew and combat situation.[18]
Line drawing of IS-2
The large 122 mm HE shell was its main asset, proving highly useful and destructive as an infantry-killer. In extremis, the IS-2 engaged enemy heavy armor with OF-471 (Russian: ОФ-471) high explosive projectiles. These shells had a mass of 25 kg (55 lb), a muzzle velocity of 800 m/s (2,600 ft/s), and were equipped with a 3.8 kg (8.4 lb) TNT charge. The explosive power could blow off an enemy tank turret, drive sprocket and tread of the heaviest German tank even if it could not penetrate the armor.[19][19][20][20] Mechanical shock and explosion was often enough to knock out enemy heavy tanks.[19]
The most recognizable disadvantage of the D-25T gun was its slow rate of fire due to the large size and weight of the shells; only one to one and a half rounds per minute could be fired, initially.[21] After some design improvements, including a semi-automatic drop breech over the previously manual screw breech, the rate of fire increased to 2–3 rounds per minute.[21] According to other sources, the increase may have amounted to 3–4 rounds per minute.[22] Another limitation imposed by the size of its ammunition in a relatively small vehicle was the ammunition stowage: only 28 rounds could be carried inside the tank, with a complement of 20 HE rounds and 8 AP rounds the norm.[23][24]
