Axiom sight in question

[Jc1]

I bought the Axiom package at the end of last season, everything is stock on it and I'm shooting the arrows and practice tips that came with the package. I've never practiced further than 20 yards. It's dead on at 20 yards. Yesterday I decided to try some shooting out at 30 yards and using the line under the crosshairs on the multiplex scope and I was consistently a good 8 inches high?
So then at 30 yards I put the center of the crosshairs on the center of the target(just like I would have done at 20 yards) and I hit the dot the size of the penny dead on?
I thought for every 10 yards, you went to the next lowest line on the sight? Or do these things shoot that fast and flat so you use the center crosshairs out to 30 yards? Hope this makes sense!
I didn't use a rest. Is it possible I'm just comfortable out to 20 yards and maybe shooting at 30, I need to take a rest at first and make some adjustments in my shooting ? Thanks in advance

[strum]

sound like some fine shooting to me but if you want to be sure then yes use a rest to make sure your solid..

some guys here will use just one crosshair (me included)and do well in hunting situations..
set the cross hairs dead on at 25 yrds and youll find you hit the kill zone from zero out to 30 -35 yards..

[FireFly]

I have a new Axiom and have been to the range for the last 4 weekends. I use a shooting stick for the same reason that I went to a crossbow and that is a shoulder problem.
I'll hit the bulls eye at 20 yards using the cross hairs, at 30 yards using the next line below the cross hairs and at 40 yards using the second line below the cross hairs.
I'm still learning how to shoot a crossbow unlike a shotgun. I'm wanting to press the stock against my shoulder. I'm learing how to rest the crossbow in my right hand, rest my right elbow against my body and use the stock and my shoulder to just steady the crossbow. Since I'm older, it's quite a learning curve.