you are not taking the thread over OB leave it where it is, if l haven't explained well enough for some to understand it may help
what you are measuring is not what l am, the neco is the only gauge out there that you can measure the case wall thickness with
it uses a chord anvil that with the deflection indicator will show variations in case wall thickness
you are right that the neco will amplify the run out due to leverage but that does not happen if you are not touching the case as in the original photos
the case touches the chord anvil sitting on it with the dial indicator sandwiching the case wall showing the thickness,
you turn the case a 1/4 turn at a time looking for differences when you let the case go, very accurate measuring
l will add a pic to show what is not seen in the original photo's
if when checking runout of the bullet you are having more than 0.0002" your case will have a big probability of being a flyer out of the group, not good
0.0005" is for plinking at best not for small groups, this may not be because of a case problem, it can happen from sizing or seating techniques
IMO to check for asymmetrical case wall thickness without the proper gauge you either check for overly thick necks on one side or after firing before sizing with your case between two v blocks check for wobble in the middle of the case with a dial indicator
or do what the old timers used to do, cull flyer cases out of the group? probably the reason they did not have huge amounts of cases, maybe 20 or so at a time
your methods eg.. rolling a round across a pane of glass is a good one for checking bullet runout because the glass will be super flat, if you paint it you will corrupt the flat surface
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