We used one this summer that was easily 100 yards from the line. The mark was a duck, we put the Uplander on a slope of a mound. It was the short bird of a water triple for field trialing.
It will throw a duck a good 10 yards with nice height. I think the back-ground would determine maximum distance.
I really like the box for hunt tests for walk-ups, diversions, wipe-outs, etc. It is small enough to tuck anywhere. It comes with velcro closures so you can put a live bird in the pouch. This is theory with my group - we hope to launch some breaking bird pigeons this weekend.
Two down sides - you do have to assemble it and getting the springs on was not easy for me and you need some upper body strength to load it.
Carol