Re: How to tell which Zoom to zero my scope on
To Zero a scope, put a target at 50 yards (or 100 if you dont have a 50 yard range), the bigger the better, but 2'x2' or so is usually good enough.
Put your rifle on a good rest. One where you can adjust the scope without the rifle moving. It doesnt have to be an expensive rest a $50 maintenance cradle or bags will work.
Take the bolt out of the rifle and look down the rifle barrel and adjust the rest so the barrel is pointing at the center of your target.
Adjust the scope so the scope cross hairs also point at the center of the target. (The major crosshairs that go all the way to the edge of the scope) It doesnt matter what zoom level (aka magnification) you are on.
Shoot 3 shots. You should be on the paper. If you aren't you need to get a bigger target, move the target closer or have a friend look and tell you where the bullet is hitting the backstop.
Once you are target, fine adjust the scope from there.