Greetings,
The horizontal lines in the reticle will give you a good estimate on the range.
If the Pnzr is as long as the reticle, it is at 1000ish, half as long, 2000ish, a quarter as long, 4000ish.
If the panzer is 1 and a half long as the reticle, 750ish, twice as long, 500ish.
It's a mil thing. 1 mil = 1 meter at 1000 meters. I think the horizontal reticle is 7 or 8 mils. (I am sure an LTAR can tell me exactly) If a Pnzr IV is 7 meters long, it will be 7 mils at 1000 meter range. 3.5 mils at 2000 meters, etc. . . .
Regards,