This normal when turning necks

[jackieschmidt]

Necking up 6to 30 is a pretty violent process. You are going to get some runout.

This is the reason I “blow out” my 6BR cases to 30.

But that has nothing to do with the .0009 case variation in wall thickness. That is totally unacceptable.

This is what they look like when ai blow them out. Dead true and ready to turn the necks.

 

[Bill Norris]

I agree it's not a pretty job and with Al if the clearance is good it may be OK but once the pressure is applied first firing the brass will straighten out. But, if the cut into the shoulder is too deep then at some point it may separate later on with several firings.

 

[searcher]

If it were me, I'd load and fire the brass, then do a skim turn on them to even out the gouge in the neck a little if it isn't too deep. It doesn't take much removal to make it look far worse than it may be. As others noted, those necks can get pretty lopsided when necking up/down. I think the step of running them through a 30BR sizing die prior to turning would have prevented/minimized that. I'd probably keep to doing it myself if that was the best I could get from the outside. But it isn't THAT bad.....

 

[ELR LVR]

I say No .
I do my 6BR Brass on a hand Foster looks much Better .
I do prep work before I turn it !!

Best though your Brass had some run out ?

Yep
Almost 99% of everyone here talks about using a Pumpkin, or a K&M or a???
But I like my Forster because turning up to the shoulder
Does not DIG INTO the shoulder.
---
Aside from not using a Forster
Your cases should iron out upon fireforming

 

[Leadfarmer]

Yep
Almost 99% of everyone here talks about using a Pumpkin, or a K&M or a???
But I like my Forster because turning up to the shoulder
Does not DIG INTO the shoulder.
---
Aside from not using a Forster
Your cases should iron out upon fireforming

Unfortunately there's like .0009 variation from the 20 or so pieces I measured. Also, I have a .332 neck chamber and with my bullet seated some pieces are giving me like .0014 clearance. Once they are fired a few times that'll be even less I imagine.

 

[ELR LVR]

Unfortunately there's like .0009 variation from the 20 or so pieces I measured. Also, I have a .332 neck chamber and with my bullet seated some pieces are giving me like .0014 clearance. Once they are fired a few times that'll be even less I imagine.

Oh gosh
Maybe fireform with the Cream of Wheat method with that little of clearance to straighten them out first
then you'll have to turn the necks again to make them all uniform
---
Curious what tool was used to initially turn the necks
With that much variation, I wonder if a lathe was used instead of traditional neck turner type tool.
There is a lot of spring back with brass on a lathe say if using a live center/no mandrel
when I turn some brass for Wildcats, I have to take like 3 ghost passes due to this.
Every ghost pass removes material, when you would think only one pass would be enough

 

[AlNyhus]

Unfortunately there's like .0009 variation from the 20 or so pieces I measured. Also, I have a .332 neck chamber and with my bullet seated some pieces are giving me like .0014 clearance. Once they are fired a few times that'll be even less I imagine.

Yeah...that's a tough one.

I've gone back and returned after firing on a couple occasions. The good thing about doing that is you have dead straight necks to work with. The downside is having a turner mandrel that fits like you want it to...since the neck I.D. is bigger after being fired. I have some in .0005's up to .3110 that work well for this. Non carbide, but you're just doing a skim cut so the heat isn't a real biggie. Loose on the mandrel isn't the end of the world as long as you don't cock the neck on the mandrel and use a good lube.

As far as a blend cut into the shoulder, a cutter angle of more than the shoulder angle helps to eliminate 'dig in'. I push the shoulders back on new brass before turning...makes the blend at the neck/shoulder smoother when it blows forward on the first hit.

Let us know what you end up doing. You definitely should contact the person that did the brass...maybe they save someone helping them? The benefit of the doubt and a polite conversation is always the best place to start.

Good shootin' -Al