If you turn necks for accuracy, when do you like to do it? On new brass or wait for once fired? Do you turn the entire circumference or just 75% or so to hit the high spots? New necks are fairly thick, .015+ so there is plenty to work with. I am also getting a donut issue by the fourth firing so when is the best time to resolve this problem?
When to Turn Necks?
- Thread starter Roninco
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Mikecr
Well-Known Member
Best to turn necks while cases are new/unfired.
But, why are you having a donut issue by 4th firing?
Neck turning won't solve the root cause of that.
But, why are you having a donut issue by 4th firing?
Neck turning won't solve the root cause of that.
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I turn unfired new. Cut to clean-up 75-90%. If you cut slightly into the neck shoulder junction, you may delay the doughnut, but that's another issue.
I posted a week ago asking how to identify the doughnut. I got some good advice then. I understand it is caused by resizing and more prevalent on some cases than others. This is a 7mm SAUM. My research says neck turning can alleviate the increased tension caused by the doughnut. If there is a way to prevent the doughnut to begin with that would be very helpful.
Joseph Wales
New Member
I was tempted and bought (cheap) once fired .260 Rem brass. Consistency was difficult to achieve, also with new Hornady brass I had similar issues. Went to Lapua and Starline Brass, no more run out issues and better groups and numbers. I bought a 21st Century case turning lathe. With a little extra TLC the Rem and H Brass now shoot as well as Lapua. Last trip to the range I had an SD of 2.1 and an ES of 5 on H Brass at a particular charge weight of Vihtavuori N555. I only knock off the high spots when I turn. I also anneal and a few others things like controlling neck tension and shoulder bumping. I sort and segregate by weight. I was challenged to determine if cheaper brass could reach levels of performance of Lapua. The answer is YES! Best SD to date with mostly untouched Lapua Brass was a 4.6. I had to stop using any Berger bullets both VLD's and Hybrids in the Sako TRG-22. Could not get decent groups and numbers. Hornady 130 ELDM's have worked the best so far in my Sako Barrel with the VV N555.
I use the Sinclair mandrel neck sizing die on the .270AI, have not had a donut problem yet. I full length resize with the expander ball out and then mandrel neck size for tension. It adds and additional step to the reloading process, but find it's well worth the effort. I turn the necks to clean up as much as possible without making the brass too thin. Sometimes I get a full clean up, and others 60-80%.
