@Stormin-Normin ,
@Bedrock Bob brings up a good point about zoom affecting the relative size of your mil dots/tic marks compared to your bullseye. I usually leave my scopes at a certain zoom level. Your scope is most likely a second focal plane (SFP) scope where the reticle pattern does not grow or shrink with changes in zoom. You can tell your type easily simply by changing the zoom and seeing if the size of the reticle changes. If not - SFP. If yes - FFP (First Focal Plane). There are a couple of things to keep in mind with these.
1) With a second focal plane (SFP) scope, when you increase magnification, your target looks larger but the reticle pattern does not. As pointed out, extra zoom might help you keep from covering up your bullseye with a round mil dot in your reticle.
2) With a second focal plane scope, increasing magnification will increase the number of mil dots (or tick marks, depending on your reticle's pattern) you need for holdover/hold under. For example, if at 4x zoom you need 1 mil dot of hold over, then when you change to 8x magnification, you will then need to use two mil dots. It's proportional. So if you were zeroed with one mil dot holdover at 4x, you would need to use two dots at 8x, and three dots at 12x.
When I make a range card, I have a few Crosman steel spinner targets (and a can of cheap, light colored spray paint) that I can set at 5 yd increments and experiment with the hold over until I know exactly how much is correct for each range and then write it down. I pick one zoom range to make my range card if I have a second focal plane (SFP) scope. Once I figure out which is the best holdover point for each 5-yard increment, I have completed my range card dope data
for that magnification. If I change my zoom on the scope, all of my dope data will change. However, if you have a first focal plane (FFP) scope, getting more popular these days, the reticle magnifies in proportion to the view when you change the zoom so the dope data doesn't change with zoom magnification level.
Hope this helps, have fun shooting!
Feinwerk