When you get to these, then you know. I have never owned a concentricity Gauge, have owned this scale. Which I could throw 200 powder charges for a 6XC and seat the bullets in 1 hour (all charges are within 1 kernel of powder of one another).
I get why people measure concentricity. The problem is does the round actually stay that way through the entire cycle from the magazine to the point you pull the trigger? I have never measured and unless you single load every round I'm not convinced it stays that way. You rifle that has a tight chamber (within reason) is going to straighten the ammo out as you close the bolt. The ammo has no choice but to take the shape of the chamber.
I'm not telling anyone to not measure concentricity, I'm saying you can probably concentrate on different efforts to make better ammo.
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