Just for grins, I went downstairs and got some real data to illustrate what I was talking about in regards to the comparator measurements not being transferable from one bullet to another.
For each of these bullets, the seating depth at which they are just touching the lands was determmined to the best of my ability (by polishing the bullet and observing for engraving with a lighted 10x loupe). Then, the dummy was measured with a Sinclair comparator. The rifle was a new Rem. Model Seven in .223. The measurements are relative, with the 50 gr. Vmax being "0" (a "+" measurement means that bullet needed to be seated that much longer according to comparator measurement than the 50 Vmax, a "-" measurement that much shorter).
50 Vmax = 0
40 B-King = +.024
40 B-tip = -.020
50 TNT = +.058
As you can see, the comparator measurement, for the SAME ogive to lands relationship, varied with this group of components by as much as .078. You absolutely can't transfer that measurement.
- DAA