Object 268 Version 4

Armament

The initial armament chosen for what became the Object 268 was the 152mm M53 gun. This gun had a muzzle velocity of 760m/s and was developed by factory #172's design bureau in parallel with the shorter 152mm M31 and M48, both of which were planned for earlier heavy self-propelled guns but ended up cancelled and never built. Unlike them, the M53 was built along with its SPG, the Object 116 aka the SU-152P, in 1948. The vehicle's trials showed that it was not accurate enough to meet specifications, and so was rejected for production. The vehicle itself was preserved and can be seen in Patriot Park.

The M53 cannon was used as a basis for a new SPG project, which was later designated the Object 268. According to preliminary calculations, the muzzle velocity of its shells would be 740 m/s. The M53 was mixed with some parts from the M62-T 122 mm tank gun. The overall mass of this system with no official name was 5100 kg.

Version 2

Version #2 of the new SPG had a rear fighting compartment, which allowed the reduction of the hull length of 6675 mm. Since the entire from of the vehicle was taken by the engine and transmission, the driver sat in the fighting compartment, to the right. The driver's visibility with this layout was not great.

These inconveniences were balanced out by the relatively short overhang of the barrel, only 2300 mm. The front of the casemate was 150-180 mm thick, the sides were 90 mm thick. The upper front plate was only 75 mm thick, but sloped at 75 degrees. The vehicle was well protected. The crew consisted of four men. In order to ease the loader's job, shells were stored in a loading drum behind the gun.

The draft of this variant, alongside the draft of the turreted Version 3, was created on April 25, 1952. It should be noted that these were created before the final draft of the tactical-technical requirements was finished, and they never officially carried the 268 index.

Version 4

The redesigned version of the 2nd variant which was indexed #4 was finished on December 18th, 1952. This design already had the index 268, and the chief designer was listed as Zh.Ya. Kotin. Externally, the 4th variant was similar to the 2nd, but the changes were significant.

First of all, the length of the hull was increased to 6900 mm, almost the same as on the Object 730. The length of the barrel overhang was reduced by 150 mm. The sloped rear of the casemate was straightened out, which increased the available size. These changes were necessary, as the new technical requirements were for a crew of 5.

The new crew member was a second loader, positioned behind the commander. The commander received a new cupola with a rangefinder and a machinegun with a curved barrel. The driver's station was redesigned, and he received new observation devices. The loading drum was left alone, but the project authors noted that the increased fighting compartment size meant that an even more powerful gun could be used. In parallel with the increased fighting compartment size, the armour protection was increased. The lower front plate was thickened to 160 mm. The front of the casemate stayed at 180 mm, but 160 mm thick cheeks were positioned at a sharp angle.The mass of the vehicle remained under 50 tons.

• The in-game Object 268 Version 4 is 75 tons, way over the 50 tons that was planned. This is likely a reference to how the in-game version has much more armor.