tomh:
Nock point placement is dependent on several factors, 1.tiller 2. how the bow is held 3. wether you shoot split finger or 3-under. 4. Drawing hand elbow height and which finger has the most pressure on the string.
I can understand Charlies statement as most bowyers tiller a bow +1/8", so if you hold and shoot each bow the same the nock point should be constant. Where you run into a snag is if the bow is not +1/8", if its zero or +3/16" nock placement will usually be different. Or if you shoot a recurve with a high wrist and a longbow with a lower wrist.
What you are trying to achieve with your nock position, is for the limbs of the bow to be bent uniformly at FULL draw. How you grip the bow or the string will alter how the limbs bend. If you use a lot of heal pressure on the grip the lower limb will bend more than if you use the straight wrist (Asbel grip). The same is true with 3-under as you hand moves down the string you bend the lower limb more. Too correct that you move the nock point up, which in turn moves your hand up and increases pressure on the upper limb. Another factor to consider if you nock under the nock point is the diameter of the shaft, a larger shaft will have a higher nock point than a small dia. shaft on the same bow.
Bob