You have to set your power ring on the big triangle . That would be a group A cartridge I think as the 300 WM is the only one close in group A .
don't appear in the list at all.
Another thing is that if you are long sighted and you need to have the ocular focus right back then that will throw off the magnification ring values . As with the focus right back the scope will have greater magnification .
If that is the case , as this reticule systems accuracy is based on the image magnification being right you may have to have the power ring on a different magnification than the instructions say . Try different settings around the big triangle setting an see what power setting gives correct hold overs . Then mark the ring with some white paint or something like that .
In future buy a First Focal Plane scope with either a Moa or mil dot reticule . You work out your own trajectory data in MOA or Mils using a ballistic program like JBM or sight it in and shoot at targets at different ranges and discover the drops . Then you can apply the holdovers required at any range on any power .
For level fire and no wind and ignoring altitude and atmospheric . You can just have a list stuck to your stock with each hold over at each range in MOA or Mils .
Get out your laser range finder range the target. Look up your list for that range and you have the hold over .
Count down the reticle subtensions that amount and that's the POI .
It works for every cartridge because you work out the trajectory of your cartridge .