Joe Salt said:
I use two bushing to sort my bullets, Its the fat and skinny ones the will kill you at long range. Pressure Difference!
This I can believe, but bearing diameter is it's own parameter just like all the others.
Diameters deltas considered from a bearing surface comparator(BSC)(JB) could be that, or bearing length, or ogive radius. Of the three different things, which is it? Or is it all three?
You couldn't assume a varying nose datum = diameter variance, or = bearing length variance.
The nose could be perfect while bearing length and/or diameter is different.
The diameter from which a perfect nose originates could be off while bearing length is countering..
If ogive radius is off neither of the other two are known from that comparator...
Three different things can combine to mean something or relatively nothing.
Now throw 'base to ogive' into consideration and the variables in combination skyrocket far from credible.
Joe, if bearing diameter is your basis of measure, sounds like a good one, you should actually measure that.
Caliper, micrometer, good indicator, go/no-go gage(holes validated w/pin gages). Maybe you do with suspect comparator readings.
Anything but assumptions from that comparator alone..
On the bullet hole block, there was someone around here recently that commissioned help to have one built. Sounded like it worked well with the hole edges taper reamed. The bullet would barely drop through one hole in the block. About that hole would be slop, or no-drop.