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8/22/2008 10:10:32 AM EDT
Getting a batch of new Winchester brass prep'd.  Have full lenght sized, primer pocket uniformed, flash hole deburred, and chamfered the necks.

Noticed that the neck wall thickness varies by at least .001 to .0015 making the ID and OD noticably non-concentric.

It looks like turning the OD will even out the wall thickness - so far - so good.  But I suspect that the entire neck is not concentric with the case body.

Any ideas on how to proceed gratefully accepted.

Thanks for your time,
OFG
8/22/2008 10:20:09 AM EDT
[#1]
The turned neck becomes concentric with the case body after fire forming.
8/22/2008 10:35:04 AM EDT
[#2]

Quoted:
Noticed that the neck wall thickness varies by at least .001 to .0015 making the ID and OD noticably non-concentric.


You have remarkable vision.  
8/22/2008 10:50:11 AM EDT
[#3]
No, not remarkable vision, access to a toolmakers microscope.  I have got to get one of those for my loading bench.

Thanks for the replies.  I was hoping that fire forming would bring things into alignment.

BTW, any recomendations for a good neck turning tool?

OFG
8/22/2008 11:22:30 AM EDT
[#4]
I like K&M.
8/22/2008 11:32:27 AM EDT
[#5]
You don't need remarkable vision to notice something like that. When your neck turner is only cutting on one side of the neck, that pretty much tells anyone that the finished neck will not be concentric with the case body.
8/22/2008 5:44:28 PM EDT
[#6]
Unless your rifle has a custom cut chamber with a very tight neck, I don't see where you're going to gain anything by neck turning....especially not with only .001" variation. It wouldn't surprise me if most chambers had more variation than that....
8/22/2008 6:05:23 PM EDT
[#7]
The technique I use.

Size in a full sizeing die, or both a body die and then neck die of good quality.  This should center the neck on the case body.  Next take the same expander that is used in the neck turning tool, and put it in your press in a special die.  This will push all the inperfections to the outside, and make a perfect fit on the expander for the neck turning operation.  Finally, I set the neck turner up to just lightly remove material, and not 360 degrees around, or you have gotten too carried away as you are now also trimming the thin side.

I agree with the above poster, that if I was reading 0.001" I would not bother.  0.002" or more and I probably would.
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