Accuracy values for the main guns - MBT's.

[JaM]

I dont forgeting FC and Rangefinder. For example if you have a T80UM tank (Crew exp 90)with FC 40 and RF 22(ACC13), you will have better accuracy at longer ranges than M1A1 tank (FC 40,RF22,ACC11 with same crew exp 90),but in reality M1A1 will be much accurate with its ammo such as M829A2 (L/D 30:1) over Russian BM-32,42 rounds (L/D 13:1-15:1).
Accuracy of ammunition is a key factor, that cant be ignored.Much more important than lenght of gun, and is a best measure of technology, gun that can handle those long rods are far superior to those that are not able to fire them. Shorter and more robust rod, the worst accuracy it has over longer distance.First soviet APFSDS rounds were 43-47mm L/D 10:1, their accuracy was bad at ranges bigger than 1500m.