Neck Runout Question

[Mule3006Elk]

When measuring runout do I measure total runout? Meaning, the sum of the positive and negative.

Example: If I have 0.002 and - 0.002 is my total runout 0.004?

I see some 1/2 this number and say it's only 0.002.

I'm not ocd with runout just trying to see which reloading steps are inflicting runout.

Just ran 28 pieces. 30-06 Lapua brass, Redding bushing die, SAC bushing, 21st Century Mandrel. Total runout (sum of + and -) of my case necks. I have not loaded them yet.

12 are 0.0015 or less
5 are 0.002 to 0.0025
8 are 0.003 to 0.0035
2 are 0.004 to 0.0045
1 is 0.006

 

[BBob]

Most common and proper used in reloading I would say is total runout. Yours is .004” aka .004” T.I.R. (Total Indicator Reading). It’s used to see how far off axis the object may be.

The half reading is Circular runout. It is generally used to see how round something might be not how far off axis it may be.

It’ll be interesting to see if TIR correlates at all between the bare brass and the brass once it’s loaded. I’m sure I did the same many many years ago but don’t remember the outcome.

 

[Mule3006Elk]

Most common and proper used in reloading I would say is total runout. Yours is .004” aka .004” T.I.R. (Total Indicator Reading). It’s used to see how far off axis the object may be.

The half reading is Circular runout. It is generally used to see how round something might be not how far off axis it may be.

It’ll be interesting to see if TIR correlates at all between the bare brass and the brass once it’s loaded. I’m sure I did the same many many years ago but don’t remember the outcome.

Thank you. Is there a threshold, say 0.004" or higher, remove from lot? In my example 25/28 have 0.0035 TIR or better. Is there any point of keeping 0.004 or higher in the mix?

These are hunting rounds, not BR, but I certainly enjoy seeing tight groups. My field shot max is 400 yards but I shoot in the off season out to 600-700 max.

I know this topic can be a rabbit hole. I understand this is not bullet TIR. Not sure if a case neck with poor TIR is worth keeping in the mix. Looking for general thoughts?