unfired-neck turning

[bench]

I turned my first brass tonight but only did 4 pieces to see how it went.
This is on unfired brass that has been fully preped.
After I turned the brass I put it back thru the forester FL die and set a bullet to check runout and the turned neck has .003 runout and the bullet has .0025 runout.
Should I not run them thru the FL die after turning,I did this to make sure the neck tension was enough to hold the bullet,this is for my AR.
I did not check a dummy round without FL sizing them again.
How do you fellas do it????
Thanks

 

[artbosco]

I turned my first brass tonight but only did 4 pieces to see how it went. ... this is for my AR.

I reserve neck turning, for tight neck chambered, custom, single shot, bolt action, competition rifles. With the AR, the magazine severely limits your potential for extreme accuracy. I believe your time would best be served pursuing other ventures.

 

[Keith Glasscock]

I would disagree with Outdoorsman from one standpoint. If the necks in the new brass are significantly off, there is some accuracy to be had. On the other hand, your neck size difference needs to be as small as possible, so you (assuming a standard no-turn chamber) would want to remove the least amount of material posssible to get thigs trued up.I turn new brass before firing, but only take enough off to just touch the thinnest neck I have. Sometimes, I have a neck that only turns 50% of the perimeter - those go into the hunting/foulers bin.

The runout after turning and FL sizing isn't significant *if* there was significant runout before turning (there usually is). A FL sizing pass is never, in my opinion, a bad idea. The turning tools tend to expand the necks to the point where there just isn't adequate neck tension for the fireforming operation ahead (at least if you are using a magazine fed rifle)

I'd recommend fireforming what you have, checking runout as fired, then resize and check again. Things should be nicely trued up if the load wasn't unreasonably light.

 

[Larryh128]

+1 on Busdriver. The only suggestion that I would have is to full length size before you do anything. Necks can certainly be out of round from shipping. What I have settled on after too many years of screwing around is a neck thickness of .013. Works with all my calibers including my AR's.

 

[bench]

Thanks guys
Tonight I start neck turning 50 once fired brass and my goal is to clean up about 70% of the neck.
So far on the test ammo I did last night on 243wssm brass most of the necks were thickest half way down the neck towards the shoulder.The mouth of the necks did not clean up.
The brass I turned in the test came out to .020,Man this brass is thick.

 

[artbosco]

If the necks in the new brass are significantly off, there is some accuracy to be had.

And ... a new Brand to be found!

 

[Catfish]

Factory chamber are over sized any way and neck turnning just shortens case life, the more you take off the fewer times time you can reload it.

 

[spclark]

... neck turnning just shortens case life, the more you take off the fewer times time you can reload it.

You know this from experience?

I've found exactly the opposite to be true, for bolt gun cases at minimum.

I can't see how neck uniforming would shorten case life. If anything, neck wall thickness variations might lead to non-uniform work hardening thru use which will shorten case life over that of cases with turned / uniform neck thickness, particularly if they're also carefully annealed from time to time.

Don't most cases end their lives by primer pocket expansion / case head stretch or case wall thinning from stretch, maybe from excessive sizing? I know for every 100 cases I send in as scrap only 1 will have a split neck.