I have that same scope mounted on a Marlin 917HMR. I zeroed it at 100yds for the center crosshairs. I haven't used the hold-over hash marks for it, as I use it for Squirrels, Groundhogs, etc but like Txhillbilly said, it for your standard loads. Just find the ammo your rifle likes, then experiment with the marks to find how accurate those marks are to your ammo. They might not be quite on at each progressive 100yd mark, but if you have a distance lazer, you'll know where those marks lineup for distance for your hold-over.