Miles, The LVR powder may be linear in its best working range but it isn't when you get out of that range. I am sure it varies somewhat from rifle to rifle as to where it works best. It is interesting that Hodgdon doesn't show loads for lighter bullets in their data. The 25-35 has 75 grain data but that is a small case. I haven't played with it enough to understand it.
Also I think the TSX is a harder bullet and is not going to correspond well with a regular bullet of the same weight. The TSX is longer too, so you have to seat it deeper and that takes up powder space.
Another thing is that lighter bullets don't always go a lot faster than heavier bullets using the same powder charge. To use up odd bullets and keep it simple, I often load lighter and heavier bullets with the same powder charge for our club high power silhouette match. I don't expect to see much difference in velocity.
Anyway to many variables to always predict accurately. I guess that's what keeps it interesting!
