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Don't use a bushing die to size brass before neck turning??

bill123

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Jun 14, 2013
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768
I read an article by German Salazar on neck tension. In it he made the following statement about not sizing with a bushing die before neck turning, "You will notice in your sized cases that there is a slight bulge [at the neck/shoulder junction]. That's because the bushing has a small bevel to allow the neck to enter without shaving brass, so the lowest portion of the neck which comes to rest in that bevel doesn't get sized as much. The bulge will have no negative effect on accuracy or brass life. However, if you plan to neck turn, then the cases should be sized with a conventional non-bushing die prior to the turning operation. That's because the neck turner would cut the bulge off, thus dangerously weakening the necks at that point and perhaps leading to a neck separation upon firing."

I haven't seen this anywhere else. Is this common knowledge?
 
It's common knowledge Bill. Bushing dies partial neck size.
Also, the only time you would downsize necks prior to turning is when you're prepping fired brass, and have no choice.
 
It's common knowledge Bill. Bushing dies partial neck size.
Also, the only time you would downsize necks prior to turning is when you're prepping fired brass, and have no choice.

Mike, thanks for the reply. I have primarily been using Zediker's book Handloading For Competition as a resource and I don't recall reading that. On new brass you won't downsize just in case there are some irregularities to work out?
 
What you drive inward with downsizing just has to be expanded right back out before turning.
But the expanding mandrel(matching the turning mandrel) might not be able to undo your downsizing.
So just expand & turn new brass as it comes out of the bag, and as the turning system is designed.
 
What you drive inward with downsizing just has to be expanded right back out before turning.
But the expanding mandrel(matching the turning mandrel) might not be able to undo your downsizing.
So just expand & turn new brass as it comes out of the bag, and as the turning system is designed.

Thanks for the help Mike.
 
I have some new Nosler brass in 270 win as well as some once fired, and have the Redding comp dies which use a bushing to neck size.

From the above it sounds like if I am going to neck size, I should do it on new brass if possible. For the once-fired brass, I also understand that I shouldn't do it on brass that has been neck sized with a bushing so that I don't create donuts.

My question is this - if I buy a Lee collet neck sizer, can I use that and then neck size? I think I will continue to use the redding bushing d=neck sizer, so I am talking about sizing the neck with the Lee after the next firing and then neck turning.

Any guidance is appreciated.
 
I read an article by German Salazar on neck tension. In it he made the following statement about not sizing with a bushing die before neck turning, "You will notice in your sized cases that there is a slight bulge [at the neck/shoulder junction]. That's because the bushing has a small bevel to allow the neck to enter without shaving brass, so the lowest portion of the neck which comes to rest in that bevel doesn't get sized as much. The bulge will have no negative effect on accuracy or brass life. However, if you plan to neck turn, then the cases should be sized with a conventional non-bushing die prior to the turning operation. That's because the neck turner would cut the bulge off, thus dangerously weakening the necks at that point and perhaps leading to a neck separation upon firing."

I haven't seen this anywhere else. Is this common knowledge?


To avoid these problems and end up with very true neck wall thickness, if possible I always
Run a conventional expander ball through the neck and then turn it (This makes the wall thickness
the same thickness all the way around. when necking up or down for wildcats I always do the turning while the case is still in it's original form so that before the neck is sized up or down. and the as the neck is expanded or compressed the neck does not move off center because of un-equal thicknesses.

So , I size the inside of the neck first, then turn it, and then size it with bushing or standard dies
for best results.

J E CUSTOM
 
To avoid these problems and end up with very true neck wall thickness, if possible I always
Run a conventional expander ball through the neck and then turn it (This makes the wall thickness
the same thickness all the way around. when necking up or down for wildcats I always do the turning while the case is still in it's original form so that before the neck is sized up or down. and the as the neck is expanded or compressed the neck does not move off center because of un-equal thicknesses.

So , I size the inside of the neck first, then turn it, and then size it with bushing or standard dies
for best results.

J E CUSTOM

Many thanks....I am new to reloading so I am not 100% familiar with various dies available - in other words, I am not 100% sure which dies have an expander ball unless it is specifically called out in the description.

Can you tell me if these dies fit the bill, and if you have any feedback on if one may better than the others?

Forster die

RCBS die

Lee collet die

Thx
 
Neck turning requires a 'turning system' that includes an expander matching the turning mandrel.
In other words, the turning system you use dictates a particular expansion tool.

Sinclair for instance offers an expander die w/mandrels as part of their turning system. Many brands rely on this same expansion. K&M includes their Expandiron die, which opens necks a little more for their larger turning mandrels.

There are situations where you need to get creative for best results. JE Custom's planning is a good example, and what I do also. Sometimes it's trial & error, which is easy enough with a few culled cases. There are many who think necks should be fire-formed prior to turning, but I have yet to see this as needed, or valid.
 
I have the Sinclair 4000 kit that has the expander mandrel - do I need a die with an expander ball in addition to that?

To give more details on where I am in my steps....with the caveat that I haven't yet reloaded a round fully and fired them. I am working thru my first cases now.

I have 50 new brass from Nosler, as of yet untouched.

I also have 140 once fired from factory ammo. I have deprimed, cleaned, and neck sized with a Redding bushing die. They all seem fine on headspace and case length.

So next steps are to prime, powder, and seat with the once fired brass. I may play with neck turning the unfired cases and save a few once fired to neck turn those - the goal here is primarily to learn on a few cases and not add it as a step until I have a few loadings under my belt.
 
I have the Sinclair 4000 kit that has the expander mandrel - do I need a die with an expander ball in addition to that?

To give more details on where I am in my steps....with the caveat that I haven't yet reloaded a round fully and fired them. I am working thru my first cases now.

I have 50 new brass from Nosler, as of yet untouched.

I also have 140 once fired from factory ammo. I have deprimed, cleaned, and neck sized with a Redding bushing die. They all seem fine on headspace and case length.

So next steps are to prime, powder, and seat with the once fired brass. I may play with neck turning the unfired cases and save a few once fired to neck turn those - the goal here is primarily to learn on a few cases and not add it as a step until I have a few loadings under my belt.


Sinclair offers two mandrels for each caliber, one is for pre-sizing the neck and the other is for turning the neck. The first mandrel sizes the neck to fit the turning mandrel perfectly for a perfect turning of the neck. This is the best way to do the job.

Other dies like Hornady, RCBS, Forester, ETC have expander balls and they work good but may not perfectly match the mandrel on your 4000 turning tool but it is better than doing nothing.

On this type of die I save the brass by simply running the expander ball out far enough that the neck sizing part of the die doesn't size the outside of the neck, or just run the brass up in the die just far enough to expand the neck.

My recommendation would be to talk To Sinclair about both mandrels for the calibers you need
and buy them.

J E CUSTOM
 
You should have the turner body, turner cutter(nearest your shoulder angle), turner mandrel, expander mandrel, expander mandrel die, and case/shell holder.
You also need a ball mic to measure neck thickness, and good judgement about target thickness.

Your new brass will be as easy as it gets to turn. This is the ideal state to begin. Just expand necks and turn, including a bit(1/32") up onto shoulders. Then size necks as you will and fire-form.

Brass that is already fire-formed can be a challenge in turning to match. How will you REALLY get it back to new form(easy to turn)? The necks are expanded and carbon fouled, and shoulders blown forward.
The turning mandrel will hate any carbon so that's gotta go.
You'll have to size-down the entire neck length(can't do with a bushing).
Then begin at the beginning with your turning system expander.
Too late to head off future donuts with turning onto shoulders so never mind that part.
 
I have both mandrels and everything that came with the kit...I think I will just size the new brass for simplicity.

Thx for the help.
 
Oregonian,

Can you tell us about your rifle? Are you going to neck turn for a custom chamber? Or is it factory chambered?

If it is not a custom chamber you might not gain anything by neck turning. You will shorten the life of the necks if the chamber neck dimension is spacious. Firing a round in the chamber expands the neck to contact the chamber wall. Sizing will reduce the neck to a dimension to hold the bullet. If the difference in dimensions is too large it will over work the brass and in just a few firings causing splits. I know I did exactly that with my first attempt at neck turning not knowing those details.

IMO neck turning should be part of a coordinated approach with chamber reamer AND neck wall thickness so uniform neck tension and bullet release clearances enhance accuracy and extend brass life.
 
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