Need some help figuring out bushing and expander ball size

[Mr Underbridge]

Finally got custom whidden sizing die with bushings and different expander balls.
I want to have about two thousands in tension on the bullet.
I have Im going to turn my necks down to 0.0127 neck wall thickness and I have 0.264 diameter bullet.
How would I go about figuring out my bushing size and my expander ball size? I guess the goal here is not to overwork the brass?

 

[powderbrake]

Typically you would load a bullet in your turned neck, and measure the diameter of the case neck over the bullet, and subtract .002. This gives the bushing diameter to use.

In this case you would not use an expander ball. I do not use expanders and can offer no advice in their use.

 

[Mr Underbridge]

Thanks but i specifically prefer to use the expander ball

 

[Bc'z]

Thanks but i specifically prefer to use the expander ball

Then get .001 & .002 under bullet diameter.
Neck wall thickness .0124 x 2 =.0254
.0254 + bullet diameter. 264 =.289
So a .288 bushing should give you .001 neck tension.
Does this sound right to you?

 

[watercam]

Thanks but i specifically prefer to use the expander ball

Curious why you need the expander ball. It can cause more problems with run-out and stress in the neck not to mention lengthening your brass each time. Semi-auto?

 

[hrlincoln]

Thanks but i specifically prefer to use the expander ball

Since you prefer to use an expander ball, I would measure the ones you got with a mic to see what you have. Might start with the smallest diameter ball to minimize working the neck, and experiment with different bushings. .001, .002, .003 under loaded round diameter for example as others have suggested. You say you want '.002' tension...your rifle might say different.

 

[243winxb]

Bushing .287"

Expander .263"

Measure a few loaded rounds neck diameter. Use a bushing .002" smaller.

No dies. Push a bullet into new factory brass, nose first. Measure.

 

[Mr Underbridge]

Thanks for walking me through the math.

 

[Mr Underbridge]

Curious why you need the expander ball. It can cause more problems with run-out and stress in the neck not to mention lengthening your brass each time. Semi-auto?

Im using a custom set of expander balls that will be matched to bushing sized appropriatley to work the brass a minimal amount unlike factory dies and expander balls?
Why? It pushes and bumps all the imperfections if any to the "outside" and makes a better more uniform surface bearing area for the bullet in my (un)scientific seat of the pants opinion.

 

[Bc'z]

Im using a custom set of expander balls that will be matched to bushing sized appropriatley to work the brass a minimal amount unlike factory dies and expander balls?
Why? It pushes and bumps all the imperfections if any to the "outside" and makes a better more uniform surface bearing area for the bullet in my (un)scientific seat of the pants opinion.

Kind of what I was thinking you were thinking.
Sounds like a plan.
Let me know how it works out.
Nothing wrong with being a non conformist, and questioning authority in my book.

 

[Jarhead6870]

Im using a custom set of expander balls that will be matched to bushing sized appropriatley to work the brass a minimal amount unlike factory dies and expander balls?
Why? It pushes and bumps all the imperfections if any to the "outside" and makes a better more uniform surface bearing area for the bullet in my (un)scientific seat of the pants opinion.

Hummmm. I may be wrong, but it was my understanding that turning the necks did away with imperfections in neck thickness. I don't turn my necks and or use an expander ball but I also don't shoot for score like many on this forum do. I am always on the search for better information so if my previously gleaned knowledge on neck turning and imperfections are incorrect, hopefully someone with more experience than I can shed some light on this.

 

[dstoenner]

If you used an expander mandrel before you neck turned then you would have moved your imperfections to the outside of the neck. Now turn your neck and those imperfections are gone.

Now you don’t need an expander ball in your sizer and your cases will be much happier.

David

 

[Bc'z]

Hummmm. I may be wrong, but it was my understanding that turning the necks did away with imperfections in neck thickness. I don't turn my necks and or use an expander ball but I also don't shoot for score like many on this forum do. I am always on the search for better information so if my previously gleaned knowledge on neck turning and imperfections are incorrect, hopefully someone with more experience than I can shed some light on this.

I believe you n all the rest are absolutely right.
But if you look at the way hes setting it up he should have minimal brass movement IMO.
Only .001-.002 brass movement makes sense to me providing it's a tight neck chamber.
Opinions please as I'm learning here.

 

[Mr Underbridge]

I don't shoot for scores, I shoot and reload for pleasure. My 308 Lapua brass is on its 15th loading. And I mostly shoot prone in the gravel and dirt.
Brass cases have all sorts of weird dings and things happen to them, mouths get deformed after so much handling etc etc etc.
I don't see the harm with using properly sized expander ball to bump the brass 0.001 inches.
So my method so far is to use the bushing to set the tension to 0.003 and use the expander ball to set the tension to 0.002, minimal amount of brass being worked.

 

[dolek]

I don't shoot for scores, I shoot and reload for pleasure. My 308 Lapua brass is on its 15th loading. And I mostly shoot prone in the gravel and dirt.
Brass cases have all sorts of weird dings and things happen to them, mouths get deformed after so much handling etc etc etc.
I don't see the harm with using properly sized expander ball to bump the brass 0.001 inches.
So my method so far is to use the bushing to set the tension to 0.003 and use the expander ball to set the tension to 0.002, minimal amount of brass being worked.

Sounds like your method works just fine .

 

[243winxb]

Brass cases have all sorts of weird dings and things happen to them, mouths get deformed after so much handling etc etc etc

Is this an auto loader?

 

[mikecr]

Your loaded neck OD should be ~.2894, but what is your chamber neck?
This can affect bushing selection for desired.

You might also consider an expander nearer to cal (.264). The necks will spring back from it, and the closer to cal the less you'll be using your bullets to finish expansion(which they're not designed for).

 

[Mr Underbridge]

with bullet and that wall thickness I will still have 0.005 neck clearance in the chamber