Variation in Neck Wall Thickness

[South Pender]

I've just bought some .270 Win. Norma brass and was curious about the neck wall thickness consistency. I took a few cases and rotated them while taking measurements with my Starrett ball micrometer. Neck wall thickness for a single round (with measurements taken at about 4 radial locations) tended to vary between about .0140" and .0135". Is this about the norm for good brass?

 

[Idaho-Lefty]

Did you run, the Expander Ball, in them, to "True" them up,.. first ?
And Chamfer them, to remove, Burrs ?
I got a pretty steady, .014 measuring in 4-5 places on each of, two cases of, 6 XC, after deburring.

 

[South Pender]

Did you run, the Expander Ball, in them, to "True" them up,.. first ?

No, I didn't do that. I ran them through a full-length resizing die first.

 

[1911nut]

5 tenths variation is pretty good.

 

[Idaho-Lefty]

Might try measuring some,.. Win and Rem Brass to, compare.
I worry about, TIR after, Bullet is inside the Neck ( Loaded ) and IF, I can get .002 -.003 Max TIR,.. I'm happy.
I have also Mic'd the Necks after, Bullet installed and find only, a couple of, Tenths Variation Max., over, neck / bullet using, Norma Brass.