Are you shooting it with a single pin or multi pin? I'm using mine with a single pin. I can shoot it much better than I can with multi pins but here lately I have brain farts and totally forget to adjust the slider from target to target. I did it twice Saturday.
I'm assuming you are getting your marks to select the correct yardage tape for your setup. I've not got one picked out yet...just using my homemade marks for now. It's definitely a good idea to not try and do it all in one day. I've been getting mine set a little at a time...between work, wind, and stormy weather it's taken me a while. I settled 60-80 the other evening. Don't be like a buddy of mine and set it up in a day...he got it "close" out to 50 and said it was "good enough" then griped about his tape not being right....and he was only going for volleyball size groups at 30-50.