Is it possible that this information is true? On this page it says that the penetration of the HEAT-FS of the PT-76 would be around 280mm instead of the 200mm it has in the game.
I leave you the piece where he talks about that topic.
``Information given in the munitions design textbook “Устройство и действие боеприпасов артиллерии” shows that the penetration of BK-354 is 209mm and the penetration of BK-354M is 280mm. Furthermore, it is stated in the article “Shaped Charges Versus Armor - Part III” by Joseph E. Backofen in the November-December 1980 issue of Armor magazine that the BK-354M round is capable of penetrating 280mm of RHA steel, coinciding with the information in the textbook.
Based on the semi-empirical shaped charge penetration by Walters and Zukas, a standoff distance of 2.66 yields a penetration of 5.0 calibers or more when a precision-made copper shaped charge liner is used on 320 BHN armour steel. With a shaped charge liner diameter of 62.3mm, this implies that BK-354M should be able to penetrate 311mm of RHA steel or more. However, because the spitback mechanism in the GPV-2 fuze introduces an additional delay compared to more modern piezoelectric fuzing systems, the nose of the shell to experiences some deformation during an impact with a hard target causing the standoff distance to decrease slightly. Furthermore, the design of the shaped charge itself with its long spitback receptacle at the apex of the shaped charge liner is not optimal. As such, the penetration power achieved with BK-354M was less than 311mm RHA.
The greater mass and dimensions of the BK-354 projectile compared to earlier conventional AP shells necessitated a 20% reduction in the propellant charge mass from 1.08 kg to 0.9 kg, so the shell has a comparatively low muzzle velocity. Coupled with the added drag from the pop-out stabilizing fins, this generates a more pronounced ballistic arc and reduces the point blank range and the maximum effective range accordingly. As mentioned before, the TShK-66 sight for the PT-76 lacks a range scale for HEAT rounds, so the gunner must refer to a range table.´´