Generally the placement depends on the rest of the buttstock, how deep it is, how much room below the cheekpiece. A maximum on an early rifle might be a pinky finger width up from the toe at the buttplate and tapered down going forward. On later rifles use you'r wife's or grandkid's pinkie finger. Just indicating these things are not precise. Draw some lines on there, compare to early rifles you see in books or on websites, and go from there. If you do a search for "Dickert" here on the forum some pictures will probably pop up that would be helpful.