During the Battle of Kursk, which, as aforementioned, saw the widest utilization of armored elements in the whole Second World War, the two powerful adversaries, Germany and Russia, had at the same time the idea of doing the same attempt: to present the armored weapon which should say the definitive word in the field of armored elements, ensuring the superiority in the battlefield to its owner. The German hopes were directed to the "Elefant" tank destroyer, which as aforementioned revealed itself as slow and vulnerable, whereas the Russian relied in the new ISU-152 self-propelled cannon. This weapon, which would give so good results that after the war it would be distributed among the armed forces of the countries adhered to the Warsaw Pact and which would remain in service until the second half of the 1950s, truly had a rather brief "gestation". In that moment the necessity of stopping the German heavy tanks armed with the deadly 88-millimeter cannon was such that Stalin in person exercised pressure over the group of designers who worked in Chelyabinsk under the direction from Engineer Kotin. The weapon which was being researched was a tank destroyer of a new formula (at least for the Red Army), namely, a cannon installed in the hull of a tank and protected by a casemate closed on its top. As aforementioned, a truly record time passed between the beginning of the research and the presentation of the prototype: twenty-five days only. The ISU, initials of Istrebitelnij Samochodnia Ustanovka (Self-Propelled Tank Destroyer), immediately demonstrated to be a fearsome adversary for the German tankers. In practice it was the result obtained from the fusion of two already existing weapons, the 152-millimeter howitzer cannon and the hull of the KV-1S heavy tank, but on the other hand the pressure from the events did not certainly allow the luxury of long research times for creating a weapon of original characteristics. The cannon was the excellent Model 1937, which was capable of firing a high-explosive projectile of 43 kilograms in weight to a distance of 17300 meters, with a muzzle velocity of 570 meters/second. Naturally, this range was never used, for in the combat between tanks the direct fire with optical aiming was exclusively used. The hull of the KV-1S was replaced in the latest models by that of the IS tank, of 46 tonnes in weight, as seen in the exemplar depicted in the illustration. Being an excellent anti-tank element, the ISU-152 had, however, a defect: the munitions, given the large caliber of the cannon, were not supplied as single pieces, but with the projectiles separated from the charges. Naturally this caused problems of space for the stowage of the reserve munitions, which were limited to 20 rounds, and exceptionally to 28 rounds. For anti-aircraft defense, and rarely for close defense, a 12.7-millimeter DSHK machine gun was installed in the top of the casemate. However, after having examined the advantages and the defects, it can be said that the ISU-152 was an excellent armored element and that it deserved the nickname which its crews liked to use to refer to it: "Zvereboi", namely, "the hitting beast".