Hailfire753 wrote:Use google earth. Go to the tools menu, and click the measureing tool. works for me. Pretty accurate too.
That really doesn't help much. All Google Earth lets you do is measure the distance between fixed points. Pacing it off is just as easy and probably just as accurate.
The tricky part of measuring range isn't finding the distance, it is finding/seeing where the projectile hit the ground.
Another way to get the range ...
Set markers out at measure distances, perhaps every 50'. The markers need to be big enough for the spotters to see, perhaps flags or, if the ground cover is short enough, bricks.
As with the water method, set spotters out laterally 100 or so feet from the gunner, the exact distance is not critical and does not need to be measured.
The spotters job is to mark where the round hit relative to the markers, i.e., "1/3 of the way from marker 5 to marker 6".
To make any kind of range measurement worth the trouble you need to have a way to measure the launch angle.