Acceptable neck thickness variation?

[savageshooter86]

How much is acceptable for competition?
Is 0.0005" variation going to be an issue? And yes I know this is limited to my tube mics accuracy.

 

[Shynloco]

IMHO, if you can get them that close, not an issue. I'd be happy with no more than .001.

Alex

 

[johara1]

If you are turning necks they should be to the .0001....... jim

 

[Tim Singleton]

For myself I don't like to see .0005" I shoot for less
That's not attempting to use a ball mic. That's measuring loaded rounds with a standard OD micrometer. It does take a while to learn to use a mic correctly.

I can't turn them to that tolerance myself. I buy them turned to the thickness I want

 

[PMA3]

For 1000 yard BR, I try to keep them +/- .0001" of my target dimension. If my target is .0105", then that number plus .0104" and .0106" would be acceptable.

 

[savageshooter86]

Thanks.

 

[Brians356]

Now that you're charged with going after no more than .0001" variance, let us know how you got there, and how you verified it.
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[savageshooter86]

Now that you're charged with going after no more than .0001" variance, let us know how you got there, and how you verified it.
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WelI already started sorting. I used an rcbs tube mic. Have a decent feel for it and marked where to put case mouth as to measure as close to same spot case to case. I measured each case in 4 spots. It's not scientific meaduring, but it's as repeatable and accurate as the tools and skills I have.

 

[Brians356]

It's not scientific meaduring, but it's as repeatable and accurate as the tools and skills I have.

And therein lies the rub. And the source of my skepticism that case neck walls can be well and demonstrably turned to within .0001" using popular dedicated neck turners. Nor do I believe that a variance as large as <gulp> .0003" can be differentiated on the target from the .0001" cases in a blind shooting test. (But y'all know about me by now!)
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[johara1]

You would be better served to get a good set of tubing mics. and learn to use them. You can get any reading you want by inconsistent pressure and feel. ..... jim

 

[Tim Singleton]

It takes a light touch and time with someone who knows to learn how to properly use a micrometer

 

[johara1]

It takes a light touch and time with someone who knows to learn how to properly use a micrometer

I use a .0102 neck thickness but by feel it could very well be .0101 or .0103 by the difference in feel but if you do it the same is uniformity and it will work is my point. Plus good equipment leads to uniformity mics. and neck turner and the right expander mandrel and learning how to deal with heat..... jim

 

[mileletron]

I think most of the measuring instruments have an accuracy of + - 0.001 "then the variation of 0.003" would only measurement error.
For example, the measure 0005 "could be between 0.004" to 0.006 ".
I may be completely fooling.

 

[johara1]

I think most of the measuring instruments have an accuracy of + - 0.001 "then the variation of 0.003" would only measurement error.
For example, the measure 0005 "could be between 0.004" to 0.006 ".
I may be completely fooling.

I think you better do some reading on the subject, when you turn necks you work in .0001 not .001 measurements...... jim

 

[Brians356]

I think most of the measuring instruments have an accuracy of + - 0.001

FYI: +- .001" would apply to a typical inexpensive dial caliper, not a typical micrometer.
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[Shynloco]

FYI: +- .001" would apply to a typical inexpensive dial caliper, not a typical micrometer.
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I think you better do some reading on the subject, when you turn necks you work in .0001 not .001 measurements...... jim

Jim,
I'm curious, what type/make of Neck Turning Tool do you use that is capable of maintaining an exact cut that holds your variance to .0001 (one ten thousandth) and not .001 (one thousands)? And then what tool do you use to get whatever measurement you come up with to arrive at the variance? Thx!

Alex

 

[johara1]

K&M and a Pumpkin......... jim

 

[John Russell]

Jim,
I'm curious, what type/make of Neck Turning Tool do you use that is capable of maintaining an exact cut that holds your variance to .0001 (one ten thousandth) and not .001 (one thousands)? And then what tool do you use to get whatever measurement you come up with to arrive at the variance? Thx!

Alex

Forster neck turning tool, power drill, and Starret 0.0001" tube micrometer.
Results in necks within < 0.0001"

 

[johnnyi]

what if you run a mandrel to push out those tiny variations? I mean after turning the next to the desired thickness... different size mandrels could be ordered for different neck tensions...
Anyway, just curious to hear the comments?

 

[mileletron]

I think you better do some reading on the subject, when you turn necks you work in .0001 not .001 measurements...... jim

You are right!
Sorry.