From you hide, the length of the RPG tube measures 2.45mils, which puts you at a distance of 388m. For your second measurement, the length of the RPG-7 overall gives you a reading of 3.4mils, and puts you at 394m. Talking an average of the two, this accurately places you at a safe distance of 391m. In reality, a third measurement shoud be taken using the height of an average male which is 1.8m, or 1800mm.