Neck turning & neck thickness

[YZ-80]

So I'm messing around with my .25-06 and since I've added neck turning to my repertoire of skills, I thought I'd turn the necks of some Winchester brass (which actually have held up quite well) as I had never turned them. They had about 6 firings on them. I got out the ball mic and was surprised to find that they were actually very consistent at .013 all the way around. So over the course of firing, I'm thinking they just got hammered into uniformity. Is this correct or do I just have some incredibly consistent Winchester brass on my hands?

 

[243winxb]

Standard dies with expander may thin neck walls. Mostly when the brass is over worked.
Measure a sized neck OD without using the expander. Measure a loaded rounds outside neck diameter.

 

[sedancowboy]

YZ-80 I would imagine that you have some Winchester brass that is consistent.
I don't think it would have improved with firing.

 

[rsmithsr]

you need more than 0.001 for neck thickness work.
an of mic that is .0001
measure a bullet at the base,
seat the bullet base half way down the neck
measure in several places

 

[eshorebwhntr]

I'm definitely not smart enough to answer this but I do think it's a good question.

If you had a new piece I guess you could measure it new, shoot it a bunch, measuring between firings, and see what you come up with?

 

[YZ-80]

Thanks all. I'm lucky I didn't have to turn them, I guess. They shot well!

 

[bill123]

So I'm messing around with my .25-06 and since I've added neck turning to my repertoire of skills, I thought I'd turn the necks of some Winchester brass (which actually have held up quite well) as I had never turned them. They had about 6 firings on them. I got out the ball mic and was surprised to find that they were actually very consistent at .013 all the way around. So over the course of firing, I'm thinking they just got hammered into uniformity. Is this correct or do I just have some incredibly consistent Winchester brass on my hands?

I have experienced the same thing and always assumed that minor variances within a neck got evened out with multiple firings. I have no proof that's what's happening though.

 

[Tiny Tim]

I think you just got a good lot of brass. Unless turning necks for a custom "tight neck" chamber, I wouldn't typically turn to completely clean up, 75-80% is all that's needed. I don't believe repeated firing will move the brass around till it flows into equilibrium. More likely the opposite may happen as the thinner and initially soft brass would theoretically thin faster.

 

[thatguyshm]

I know some people preach to only turn after the first firing, assumably to allow the brass to settle. Maybe it will move on its first firing, but I have turned lots of new brass that is over 2-3k difference in different spots, clean it so it's within 1k and it doesn't flow any after turning it. I don't believe you'd have moved it that much, just lucky.

I mainly turn now when I neck brass up and am concerned about shoulder doughnuts or in the case of the last winchester brass I bought, one side was 0.015" and there were low spots at 0.011". Cleaned it up to 0.013" and moved on. It was 338 Winchester hunting brass.