1400 is a chipshoot for the Bushnell Fusion's so I haven't had a problem, but 1200 used to be the max I could hit with the Elite 1500 ARC, and so when we would set up a KD series of shots, we would do the "both ways" method.
Get in between, and lase the target one way, and the truck the other way and add em together. It's not 100% accurate, depending on the line of sight...but you can factor that in as well using the angle each way and some 5rd grade math. It's usually not as far off as you might imagine.
Another way is to plug in your spots on Google Earth or even GPS them on Google Maps from your phone. That gives surprisingly accurate estimations, usually within 25 yds +/-
(I haven't noticed to much issues at 12-1400, but when you get out beyond a mile...+/-25 isn't good enough)