[Mobhack]

Mobhack is not a calculator - its an editor. The value there is the base AP value.

APcalc is a calculation, based on 1000 rounds "fired" via the game code. Its an average of the 1000 rounds, so the value won't be the same as the base value, since HEAT is an unreliable chemical munition. The 1000 shot average therefore is quite likely to fall below the nominal value shown in Mobhack. the "best" figure for HEAT will show the best round out of 1000 with no saying whether 1 or 5 or so rounds achieved that score.