I'm making a hit probability table for the T-55 (with standard 100mm cannon) and FAS is giving me conflicting information.

http://www.fas.org/man/dod-101/sys/land/row/t54tank.htm

What is the difference between maximum aimed range and effective range? And if the ammunition says its max range is 2500m, does that change anything or is the tank the limiting factor in this equation.

Effectively, the website is telling me a normal round's max range is 2500m, the max aimed range is 2000m, and the max effective range is 800m.

I need to pick a range that a typical T-55 would have a 100% chance of hitting a tank sized object, then increment the percent of a direct hit all the way down to 10%.

If the terms are similar to IDF terms than:

Max range: The longest possible range a projectile from the tank could travel.

Max aimed range: The longest possible range at which you can aim and hit using the tanks optic sights and fire control system.

Max effective range: An estimated range at which the ammunition can effect(read destroy) the target. For AP shots this is far shorter than the max aimed range. For HEAT and HESH it is theortiacally equal to aimed range.

As far as the natural dispersion of rounds from a 100mm gun I have no idea, sorry.

By "typical" i'm guessing you mean the original basic version with the wz 1944 pattern canon, the max range was 3000m, the rest is about right, effective fire would be typically under 700 meters regardless of the optics since the gun stabilisation was practically non-existant.

If you're interested in a particular model (for example Egyptians replaced their original guns with an American 105mm one) name it and i'll be able to provide more info.

So FAS is saying any AP round fired at an object over 800m will not do significant damage? Wow this tank is going to get raped in my sims.

Thanks alot guys

The longest recorded tank killer shot was fired by a Challenger Tank in the Gulf War at over two miles