Wikifail is no god for data posting.
"The American M26 Pershing (using tungsten HVAP ammunition), the British Comet with the 77 mm gun, and the Soviet IS-2 (using steel shot) had to be within 1300 m, 500 m and 200 m respectively. "
i found this "The crew was protected by thick sloping armor that made it a hard target, and only a few weapons were actually able to destroy it at even close range. There are no records or photographs to prove that the Tiger II’s frontal armor was ever penetrated in combat."
From
http://www.achtungpanzer.com/ a way better page for tank data than wiki.
So whos right?? you or me? see tank effectiness can change a lot depending whos writting.
The ISU 152 fires HE rounds so while the explosion may destroy the tank it has small penetration power. The 122mm on the IS3 has the power to kill the KT. Try autoaim for weak parts. KT has 150mm sloped armor so thats around 250/280mm effective armor. A lot for WWII era guns. Especialy that fail russians guns that carried sup par ammo.
Also flank!!!! Germany got the best guns/armor combos in game. At medium distances even the panther will stop your rounds.