Originally Posted by sweet old bill
.... if not what are you using and how do they work ????
I'm using Pin Wheel software which has a number of ways to get a tape.
Two ways I've tried that work well for me:
One way is that I shoot two differant yardages making temporary marks then measure the distance between those marks and feed it to the computer.
The other way is to measure the peep height and sight radius along with the results of a chrono (I bought a light kit for the chrono for better precision).
I've had great results with both methods with one exception which was off 3 yds @ 40. I believe the error was caused while trying to measure the peep height on a fat shaft suspended on a lizard tounge while the bow was held horizontally in a draw board. The next time I do that type of set-up the arrow will be clamped to the riser via an adjustable parrallel or the board will go verticle.