Above you see the "aiming help" or recticles the Germans had in their Zeiss Optics. Its an early version, the later version differed a little in layout, but the functionality remained the same. Note that the gunner only saw the 4 small and the large triangles, I added the description to explain their use.

What you have to understand is that the shell travels in an arc. The shape of the arc is dependent on the muzzle velocity among other things. Late German guns had a very high muzzle velocity and traveled in a stretched arc which gave the Germans more advantages than just penetration power.

In World War II there were no laser range finders. The gunner had to rely on his sight in the scope to judge distance to the target and to raise or lower his gun accordingly to increase the range the bullet flies. If the gunner raises his gun the bullet flies far, lowering does reduce that range. Sounds easy, right? Wrong. How did they guess the distance?

How to aim at a T-34 (from the Tigerfibel)

Take a look at the center large triangle. That triangle was calibrated to be "4 Strich" (in German) wide, or 4 mils. On 1000 meters range one mil resembles 1 meter if the gun was properly calibrated (thats a big "if"). Lets say there is a target 4 meters wide. Align the center triangle to the target and see if its larger or smaller and reduce the range accordingly. If the target is half the size of the triangle its twice a far away, ie. 2000 meters. If it is covering the large triangle and a small, ie. 6 mils wide, its:

4 mils = 1000 meters for 4 meter size, 6 mils = 750 meters for 4 meter size

So all you got to do is to know the targets size and match it against your sights. The small triangles are 2 mils, the large 4 mils, the distance between the small is 2 at their base, 4 mils at their tip. German gun crews knew the size of their targets from target tables and later instinctively knew distances. They practiced with their thumb all the time. Your thumb is on average 40 mils wide on 1000 meters, if you stretch your arm. Try it and guess ranges and verify if you're right or wrong. When aiming use the left and the right eye and the thumb will switch "targets". that jump is 100 meters or 100 mils at a distance of 1000 meters on average.

Now the exact range is NOT the range you want to aim to. Why? Because the shell would hit the ground exactly in front of your target, the range you guessed. But you want to HIT the target, ie. you have to aim higher. In order to hit the gunner has to change his "Visier" (turn the range wheel) of his sight which raises or lowers the aiming sight shown above, thus forcing him to lower or raise his gun to set the aiming sight again on target. The aiming sight of the Panzergranate 39 (Armor Piercing ammunition) was ranged form 0 to 4000 meters. Note that there is a different aiming set for each ammunition the tank carried because its flight path differs from the different muzzle velocity. Tanks with early Zeiss optics needed to add/deduct from their guessed range for each ammo type while later ones had different recticles for each.

Its not as easy as its sounds. Some more factors are playing in. On sunny clear days targets seem to be closer, on dawn or cloudy days targets seem to be further away. If a target drives you have to aim in front of it because the bullet needs its time to reach the target. Muzzle velocities of 750 meters/second means that the shell needs 1.3 seconds to reach its target. A tank driving with 25 km/h travels 7 meters in 1 second. You have to take that into account.

German gunners were known to hit weak spots on enemy tanks. The gunner in German tanks sits to the left of the gun (to the right of the gun in American tanks). So the gun shoots a little over 70 centimeters to the right if you aim perfectly. The machine gun even hits over 1 meter to the right of the spot you aimed at. Also the shell is set to a spin and that spin will force the shell from its ideal path slightly to the left and down. Ask an Engineer why that is. all those factors were trained properly and the german gunners were experts taking those into account during combat. In order to calibrate their guns they bore sighted it against a target they knew the size and range. They calibrated the optics to that target and test fired a few shells.

Now analyzing what a higher muzzle velocity meant is simple. Besides having a higher penetration power it also allowed a higher margin of error in range guessing. Because the shell was flying in a stretched arc you can guess wrong up to 200 meters and the shell still hits your target because when aiming too high simply raises the aiming point by less than a meter, still small enough to hit a 3 meter high tank when aimed at its center.

Because you can see where your shell hit you immediately know if you guessed too high or too low. If you have a good sight to the target you can even judge the exact distance you miscalculated and thus can correct your sight and refire. That's why most experienced crews on German tanks could guarantee a hit on the 2nd shot. Variation in gun powder and differences between guns allowed precise shooting under 1000 meters, while those factors added a random element beyond 1000 meters. Shots beyond 2000 meters were considered lucky hits, at 4000 meters pure luck.

The longest confirmed kill to our knowledge was 14 kilometers. It was shot by an 88 Flak in the desert war vs. the British forces. When analyzing the above shooting procedure you know what they had to do in order to hit. They had two large "V" shaped optics in an exact distance from the Flak positioned. Both guessed the range and triangulated theirs to set the Flak to the fire range. The Flak shot and they observed the miss and corrected accordingly until they hit their target.

The americans had poor optics and could NOT measure the range through them. All shots beyond 800 meters were lucky guesses on their part.

This is an excerpt of an article originally posted on the Wings Simulations web site.