Neck Thickness- dumb question probably

[Brians356]

Like Matt, I turn them when there new, which puts the "stop point" into the shoulder when fire-forming, which eliminates donuts and tapers that can be caused from a turners stop point.

I think that's a good approach with so-called "premium" brass (e.g. Lapua, Nosler) but with generic brass the necks are in less than optimal shape for turning, they really are "raw". Firing them once really rounds them out better than employing a mandrel, but it does also advance the neck/shoulder junction as you point out.

So do you find that, say, Lapua cases come sized perfectly for your turner mandrel, or do you need to adjust the neck IDs using a mandrel and/or die?
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[dkhunt14]

I think that's a good approach with so-called "premium" brass (e.g. Lapua, Nosler) but with generic brass the necks are in less than optimal shape for turning, they really are "raw". Firing them once really rounds them out better than employing a mandrel, but it does also advance the neck/shoulder junction as you point out.

So do you find that, say, Lapua cases come sized perfectly for your turner mandrel, or do you need to adjust the neck IDs using a mandrel and/or die?
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You need to run on a mandrel because they are really tight. At least the 6 BR are. Matt

 

[dmoran]

@brians356 -
"So do you find that, say, Lapua cases come sized perfectly for your turner mandrel, or do you need to adjust the neck IDs using a mandrel and/or die?"

In my own experience, all brass/brands are subjected to out-of-round and/or dented case necks, that need expanding/ironed-out prior to any neck steps such as neck-turning or chamfering of the case mouths.

I do it to all new brass no matter if I'm turning the necks or not, to ensure equal chamfer all the way around the case mouths. I'm setup with a K&M expander die and expander mandrels.
Donovan

 

[Brians356]

If they come good and tight in the neck, then an expander mandrel which is nominally sized .001" (e.g. Sinclair's ) under bullet diameter would take care of any roundness or dent issues. I think you've turned me 135-degs anyway.
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