Told you I had to have one, put it on my 300RSAUM with 180gr SST at 2800FPS and the scope set on 148 off the chart that comes with the scope it gives me a dot out to 720yds at 730yds it lights up the bottom 3 dots which means past the compensating range. Pretty darn accurate too, at 700yds it gave me a 8"group about 2" low, not too bad for a lightweight hunting rig (REM model 7 22" barrel).
I could range deer size rocks and bushes out to 800yds every try, the farthest I got was 986yds off a small shed. I had to put a small piece of foam behind the battery to keep a good contact with recoil, if thats the only problem it has I have no complaints at all!