When turning necks on cases what's the minimum OD on 30-06?

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Bexar

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Turned some cases and on about every third case I would get a split neck. Is there any spec. on minimum OD?

Load was a standard load that worked fine in unturned cases.

Thanks,

Bexar
 
Just need to skip case necks to make them consistent. Sounds like taking way to much off making them to thin causing splits. Do you have a ball mic to see how thick the necks are? Do you use concentric gage to check neck runout ? Is this for a match chambered rifle that needs neck turning?
Just couple thoughts
Roc1
 
30-06 loaded round neck diameter. Outside turning.

From what i read, .328" neck diameter of a loaded round would be the minimum. This gives about .010" neck wall thickness.. But i would not want less then .332" for a factory chamber. SAAMI SHOWS A MAXIMUM NECK DIAMETER OF .3397" But it would be a rare find at the max.
 
Turned some cases and on about every third case I would get a split neck. Is there any spec. on minimum OD?

You shouldn't be turning off so much brass that some is turned off all the way around on every case. On most of the cases, there should be some brass that is skipped over.
 
Unless you actually know your chamber neck turning is sort of a waste. You really need to know your chamber dimensions, why bother to turn a neck? Tight neck chambers are turned that way or better put reamed that way, you then turn the necks to mate with the chamber. YTou could make a chamber casting using for example BROWNELLS - CERROSAFE® CHAMBER CASTING ALLOY and better know what you have before turning necks. That being my thinking anyway.

Ron
 
SAMMI spec is .3397". No tolerances given.
As mentioned, annealing is probably what you need to do, but there isn't much need to turn .30-06 necks. Turning is usually done only when forming other cases out of .30-06. .270, for example.
 
I don't think one needs to turn case necks to get zero spread in their thickness until their worst groups at 100 yards are about 3/10ths inch.

Even with case neck wall thickness spread of .002", bullets won't be off center in the barrel more than .001" on perfectly shaped cases with neck, shoulder and body in perfect alignment.

Sierra Bullets does no such prep on cases used to shoot their bullets for accuracy tests. Their best match bullets go into 1/2 inch at 200 yards; one 10-shot group after another.
 
Thanks for the responses and info. I'm probably not going to do it anymore or if I do I'll follow the skip suggestion. I prefer to neck size only and this was an attempt to get a little more "OCD" :p uniformity.

It's not even for my rifle but our Daughter's; and she hasn't reached the point yet to enjoy precision. She's more interested in the young buck range officers. :)

That dang "OCD" not leaving well enough alone has been my proverbial monkey. :p
 
If you're truly "OCD" about uniformity in reloads, you'll properly full length size your fired cases and forget neck sizing. Virtually all of the benchrest folks did that some years ago. High power match rifle shooters have been doing that since the 1960's. Case necks are straightest on resized cases when the whole case is held in alignment; neck, shoulder and body.

Proper full length sizing didn't change the size of smallest groups fired. But the biggest ones shot shrunk quite a bit. The smaller your biggest groups are, the more often a very tiny one will happen.

Once one understands how bottleneck cases fit the chamber when fired, they'll understand the benefits of correct full length sizing of bottleneck cases. I've always got better accuracy with new cases versus neck only sized ones.
 
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