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Expander Ball Effect on Brass Test

Phil3

Sergeant
Full Member
Minuteman
Dec 13, 2008
402
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San Ramon, CA
I am new to reloading, and am hardly a professional researcher, but perhaps the test described below will shed some quantifiable light on the effect of an expander ball on brass.

The cases I used were Blackhills 223 Remington twice fired. The tools that were pertinent to the test include a Redding FL sizing die, optional carbide expander ball, Forster Co-Ax press, Imperial case lube, and Imperial media dry lube for neck interior. Wilson Sinclair case trimmer was also used.

All cases were trimmed to 1.750". Fire formed case neck diameter was .254" (average - some case neck thickness variation). Shoulders were bumped back a few thousandths. New set of three fire formed cases used for each test, except test #3.

Test #1 - FL resize w/expander using neck lube. Case lengthened by an average .005".

Test #2 - FL resize w/expander using NO neck lube. Case lengthened by an average of .005".

Test #3 - Trim brass from test #1 and #2 back to 1.750" and repeat test #1 and #2. Case lengthened by .001".

Test #4 - FL resize without expander ball. Case lengthened by .006".

At first, it appeared that the expander ball does drag on, and stretch the neck. But test #4 shows the case lengthens without it, perhaps due to the die forcing the brass having to go somewhere (up, into neck area).

Test #3 used already sized brass, AND it had an expander ball. Since no resizing is necessary, and if the resizing is actually causing the brass to lengthen, then one would expect no change in this test. In fact, the brass grew by just .001".

As an aside, the expander does work the neck. My fire formed brass measured about .254" on the neck. Without the expander ball, the neck is pushed down to .240", and the expander ball brings it back .246".

Is the expander ball a bad thing? To my mind, no, at least when it is carbide (which is MUCH smoother and easier than steel), but welcome other's perspectives.

- Phil



 
Re: Expander Ball Effect on Brass Test

Interesting indeed

I would like to purchase a carbide expander ball.

Any thoughts on the imperial dry sizing die? Was contemplating putting an order for it next time im procuring from sinclairs.
 
Re: Expander Ball Effect on Brass Test

Get rid of expander balls alltogether.
They are poison on accuracy , case life , neck hardening .
They over work the brass.
The design came about so that casese with different neck thickness can all be sized with one die. The cost for that is to wear out the case and harden it up. The ammo manufacturers love them.
They are not a bad thing as they do a specific job but there is better ways to reload ammo.
However if you lapp the die and possibly the expander ball also so it only sizes the minimum amount to reload then that takes a lot of work hardening off the case neck. Reducing the amount that the ball has to reexpand also reduces stretching and pulling necks out of line.
 
Re: Expander Ball Effect on Brass Test

I agree and disagree on some of your points Country, but I have found the use of the Redding carbide floating expander has reduced my runout, by selecting a bushing that allows the floating ball to barely kiss the inside of the neck, since we don't neck turn the .002 less than the bullet ball smoothes the inside of the case making it round, some brass is pretty uneven in thickness, just using the bushing makes the outside round, and the inside uneven, the ball fixes this, I'm not talking about pulling the ball thru hard, but just barely touching the inside, Monty M who I trust on all matters of reloading enlightened us on this subject before, I tried it and liked it
 
Re: Expander Ball Effect on Brass Test

I have stopped using expander balls completely, I can't see how they can possibly be good for case life and accuracy. Half the time they are not even concentric to the die.
Now I prefer to use a body die to just bump the shoulders back and then neck size with a Lee collet die.
 
Re: Expander Ball Effect on Brass Test

I think the Lee Collet die is a good idea, but it most definitely over works the brass
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Evilaviator</div><div class="ubbcode-body">Use a mandrel in place of an expander ball. </div></div>

Now you're thinking.

Working off the ID rather than the OD creates a more consistent neck ID, the part the bullet touches, as neck thickness has little affect on the end ID when the ID is used as the last thing a sizing tool touches.

This makes a strong arguement in favor of a bushing die and expander ball, used in two steps, or a bushing die and a mandrel, again used in two steps (bushing first in both cases).

As I don't neck turn, expander balls are the better solution for controlling neck tension than no expander and just a bushing.
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">I think the Lee Collet die is a good idea, but it most definitely over works the brass </div></div>

I have experimented with once fired brass out of different rifles and found that some need more work than others. In some cases the brass is almost too large to go into the collet. In these cases the brass is definitely being overworked and the rifle it was fired from has a chamber on the top dims.

Must be lucky as with all of the cases fired from my rifles however as I find only minimum amount of work goes into resizing the neck. My aim is to work the brass as little as possible while keeping runout to a bare minimum.
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jagged77</div><div class="ubbcode-body">I have stopped using expander balls completely, I can't see how they can possibly be good for case life and accuracy. Half the time they are not even concentric to the die.
Now I prefer to use a body die to just bump the shoulders back and then neck size with a Lee collet die. </div></div>

It does appear that the FL die and expander ball work the neck quite bit, mashing it down from .254" to .240", and then back to a final dimension of .246". However, stretching of case from the expander seemed to be quite minimal (w/carbide button), if my conclusions are correct.

Please note that the carbide button in the Redding FL die floats and can align itself with the case as it needs to.

My next test will be see what happens to neck runout by sizing with an expander ball vs not.

- Phil
 
Re: Expander Ball Effect on Brass Test

You are missing the point - you have control over how much the die and expander work the brass. You just have to buy gear that incrementally works the brass the amount you want it to.

Unquantified over-generalizations are misleading and of little use. Switch from adverbs and adjectives to empirical data to add meaning.

The biggest factor in your neck being worked has nothing to do with the dies or expander - it has to do with the neck ID of your chamber. The largest change in dimension occurs when you take a fired case and size it down under bullet diameter with the die or bushing in the die. The expander then brings it up a few thou from that.

You can control all 3, PLUS brass neck wall thickness - how you go about getting the dimension you want prior to inserting a bullet is best served with tools touching both the inside and outside of the neck.

 
Re: Expander Ball Effect on Brass Test

How does the Lee collet die 'overwork' the brass so badly?
If they generally squeeze the neck down around to give .002" neck tension, how is this working the brass much more than a bushing selected to give the same .002" tension (without an expander)?

The collet is simply squeezing around a hard mandrel isn't it? The mandrel isn't expanding the the neck diameter at all?
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: _9H</div><div class="ubbcode-body">You are missing the point - you have control over how much the die and expander work the brass. You just have to buy gear that incrementally works the brass the amount you want it to.

Unquantified over-generalizations are misleading and of little use. Switch from adverbs and adjectives to empirical data to add meaning.

The biggest factor in your neck being worked has nothing to do with the dies or expander - it has to do with the neck ID of your chamber. The largest change in dimension occurs when you take a fired case and size it down under bullet diameter with the die or bushing in the die. The expander then brings it up a few thou from that.

You can control all 3, PLUS brass neck wall thickness - how you go about getting the dimension you want prior to inserting a bullet is best served with tools touching both the inside and outside of the neck.</div></div>

No point missed. The sole purpose of the post was to show in quantifiable terms what happens to brass with the tools and setup I stated in the test. I drew my own conclusions and welcomed others to do the same. Nothing more.

The test was not a discussion on other ways of controlling neck dimensions, all of which I am fully aware. As an aside, your point on the neck seeing the largest dimensional change when sizing a fired case was made clear in my original post. The stated dimensions show that.

- Phil
 
Re: Expander Ball Effect on Brass Test

Expander ball doesn't cause the case to stretch....

When you FL size your brass the body of the brass is made smaller along with the shoulder being pushed back. Brass ain't magic metal, it has to go somewhere when resized. It grows in length.
wink.gif


The larger the chamber the more the brass will flow. That's why some folks have special re-sizing dies made to match their custom chamber reamer.
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Expander ball doesn't cause the case to stretch....</div></div>

On my test, that would appear to be the case, and was my conclusion (with my setup). As the test shows, when I resized brass that was ALREADY resized, the case lengthened by .001". Not sure why, but that was a lot less than the .005" when it was resized from a fire formed condition, causing me to conclude the resizing (not expander) adds to length. I need to test this with the original steel expander bass, as that dragged much harder through the neck than the carbide button, so much so, I really have to wonder if it would cause case neck stretch.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">When you FL size your brass the body of the brass is made smaller along with the shoulder being pushed back. Brass ain't magic metal, it has to go somewhere when resized. It grows in length.</div></div>

Perhaps very dumb question...but why must the displaced brass add to length? Why not just displace to the inside? Not disputing it adds to length (my test seems to indicate that is true), just wondering why.

- Phil
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gfunkUK</div><div class="ubbcode-body">How does the Lee collet die 'overwork' the brass so badly?
If they generally squeeze the neck down around to give .002" neck tension, how is this working the brass much more than a bushing selected to give the same .002" tension (without an expander)?

The collet is simply squeezing around a hard mandrel isn't it? The mandrel isn't expanding the the neck diameter at all? </div></div>

Not wishing to hijick the original thread, but in reply to gfunUK - in some cases if the chamber dimensions are on the top end, the collet can be very aggressive in sizing the neck down and can make a horrible mess of the brass. If the chamber is on the tight side the fired brass will require less sizing.

Phil 3
I would be very interested to see the run-out results when you have completed them. For me, working and hardening the brass using a F/L die and expander ball can be overcome with trimming and annealing. However straightness of the finished case and consistent neck tension is of paramount importance.
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Phil3</div><div class="ubbcode-body">
Perhaps very dumb question...but why must the displaced brass add to length? Why not just displace to the inside? Not disputing it adds to length (my test seems to indicate that is true), just wondering why.

- Phil </div></div>

Phil, it takes the path of least resistance and flows along the grain structure (grain flow).
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Perhaps very dumb question...but why must the displaced brass add to length? Why not just displace to the inside? Not disputing it adds to length (my test seems to indicate that is true), just wondering why.

- Phil

</div></div>

The brass is encapsulated in the sizing die, only one way for it to go.
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Phil 3
I would be very interested to see the run-out results when you have completed them. For me, working and hardening the brass using a F/L die and expander ball can be overcome with trimming and annealing. However straightness of the finished case and consistent neck tension is of paramount importance.</div></div>

Some random testing did not show promising runout results (.003 - .004"), but I was tired at this point and may have been careless. The test will be more complex. The expander ball pushes all neck thickness variations to the outside. Therefore, runout can be a result of the neck not being concentric to the case body, AND/OR a result of case neck thickness variation. I know some of the cases have necks that vary .001" - .002" if I recall correctly.

I have a neck thickness measurement tool. I will look for brass that have minimal variation and use those cases to measure neck run out. I can not neck turn as I do not have those tools.

The test will determine what happens to runout with and without an expander ball.

Stay tuned, and thanks for your interest.

- Phil
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Not wishing to hijick the original thread, but in reply to gfunUK - in some cases if the chamber dimensions are on the top end, the collet can be very aggressive in sizing the neck down and can make a horrible mess of the brass. If the chamber is on the tight side the fired brass will require less sizing.</div></div>

Ah I see, I have never encountered this problem before, but see what you mean.
I guess if you have a large dimension chamber there's no getting out of working the brass then, as you HAVE to size the brass down enough to get desired neck tension. Whichever method your using.

Back on topic,
Thanks for taking the time running your tests Phil, I too will be interested in your runout conclusions!!
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Evilaviator</div><div class="ubbcode-body">Use a mandrel in place of an expander ball. </div></div>

+1. That is how I reload my accuracy reloads. I use the Sinclair mandrel. Cut my bulet runout in half. Tom.
 
Re: Expander Ball Effect on Brass Test

I use the ball and F/L resizer die, but I employ them with a twist.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">
I take a stab at regulating/managing it by backing off the F/L die and adjusting the amount of neck length getting sized in accordance with the marginal inability to spin a seated bullet between index finger and thumb. There's some direct feedback inherent in the process that turns neck tension into something a bit more substantial than by guess and by gosh.

True F/L resizing is only performed once bolt closure drag on a significant percentage live rounds becomes significantly noticable.</div></div>

Greg
 
Re: Expander Ball Effect on Brass Test

Last night, I took one once-fired case and resized it with the expander ball in place. It did grow by about .005", consistent with my original test results. But, wanted to further explore further the effect of the expander on the neck. I have read so often how the ball dragging through the neck stretches it.

I took the resized brass and ran it through again with expander in place. I did this four times. Each time, the neck was squeezed down to .240" and brought back to .246" after the expander went through.

After four resizings with carbide expander (on already resized case), the case lengthened .001".

I stopped after four passes as the neck brass was becoming quite shiny, perhaps to due to being worked as much as it was. I don't know, but did not want the case to come apart in the die if this was some sign of metal fatigue. Needless to say, I tossed this test case after all I put it through.

As stated earlier. next test is effect of the expander on neck runout. I started prepping and sorting cases last night and will report those results as soon as possible on another post.

- Phil
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HOGGHEAD</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Evilaviator</div><div class="ubbcode-body">Use a mandrel in place of an expander ball. </div></div>

+1. That is how I reload my accuracy reloads. I use the Sinclair mandrel. Cut my bulet runout in half. Tom. </div></div>

Can you explain how this is done (mandrel vs expander ball)? I don't think you are talking about a mandrel somehow used in the die, but not sure how this would work. I am trying to understand how a mandrel will keep the neck ID concentric with the case body.

- Phil
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Phil3</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HOGGHEAD</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Evilaviator</div><div class="ubbcode-body">Use a mandrel in place of an expander ball. </div></div>

+1. That is how I reload my accuracy reloads. I use the Sinclair mandrel. Cut my bulet runout in half. Tom. </div></div>

Can you explain how this is done (mandrel vs expander ball)? I don't think you are talking about a mandrel somehow used in the die, but not sure how this would work. I am trying to understand how a mandrel will keep the neck ID concentric with the case body.

- Phil</div></div>

I'd like to know this as well.

This is a great thread by the way, my groups have been opening up a lot about 1.25 MOA, nothing in my process has changed so I am sure it has to do with neck tension. I'm still trying to figure out this expander ball theory.
 
Re: Expander Ball Effect on Brass Test

Thank you for posting these results, Phil3. It is a good reminder of what we often read in reloading texts, but which may not be accompanied by numbers for quantification.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jagged77</div><div class="ubbcode-body">Not wishing to hijick the original thread, but in reply to gfunUK - in some cases if the chamber dimensions are on the top end, the collet can be very aggressive in sizing the neck down and can make a horrible mess of the brass. If the chamber is on the tight side the fired brass will require less sizing.</div></div>

Jagged77, it is true that some chambers are cut 'loose,' and that brass fired through those chambers will be worked more upon resizing. That is _not_ an indicator that a Lee Collet die 'overworks' the brass. It does not. A Lee Collet die performs the minimum possible working of the brass.
 
Re: Expander Ball Effect on Brass Test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Iggy.</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Phil3</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HOGGHEAD</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Evilaviator</div><div class="ubbcode-body">Use a mandrel in place of an expander ball. </div></div>

+1. That is how I reload my accuracy reloads. I use the Sinclair mandrel. Cut my bulet runout in half. Tom. </div></div>

Can you explain how this is done (mandrel vs expander ball)? I don't think you are talking about a mandrel somehow used in the die, but not sure how this would work. I am trying to understand how a mandrel will keep the neck ID concentric with the case body.

- Phil</div></div>

I'd like to know this as well.

This is a great thread by the way, my groups have been opening up a lot about 1.25 MOA, nothing in my process has changed so I am sure it has to do with neck tension. I'm still trying to figure out this expander ball theory. </div></div>

First off I take the complete expander ball and stem out of the die. I decap the primers with a separate decapping die.

Then I size the brass. I normally just like to bump the shoulder slightly but do it differently for different cartridges and different firearms. In some rifles I do a full length resize.

Then in a separate step I use the Sinclair sizing mandrel. This does not put any stress or pressure on the shoulder at all-like the expander ball does when you pull it back through. I use sizing wax in this step. I think the expander ball pulls the neck off to one side or the other and that is where the runout if affected.

The mandrel "lines up" automatically with the center of the brass, and since there is no pressure on the shoulder the brass can move around slightly in the shell holder so that it aligns straight with the mandrel. And the mandrel sizes the inside of the neck exactly the same every time. So not only does it reduce the runout, it also gives more consistent neck tension. And better SD's because of consistent neck tension.

I was always having problems with runout. Regardless of what I did. So one day I was discussing this with one of the guys at Sinclair(the old Sinclair). And he told me to try the mandrel method. I did, and I am glad I did.

Now you need to realize this adds two more steps in the reloading process. So if you are in a hurry then it is not the way you want to go. But I am in no hurry, and my emphasis is on accuracy. And the reloading bench is one of my favorite places to be. So I do not mind the extra steps.

All I know for sure is that my runout decreased by more than 1/2 on the finished cartridges that I checked the runout on. And my SD's were reduced(slightly). Tom.
 
Re: Expander Ball Effect on Brass Test

I accept that expanders can be associated with runout, but I think it may have as much to do with off-center decapping rods as with the ball itself. In any case, I make a point of polishing the ball and keeping it clean and bright.

While some have managed to demonstrate linkages between runout and accuracy, my own testing fails to deliver this outcome. The reasons could be many, not exempting flaws in my own testing methods.

My point being that I now shoot SAAMI chambers intentionally and exclusively, and do not bother with any ogive or runout -related factors. There are undoubtedly some accuracy sacrifices; I just don't seem to see enough to warrant extraordinary measures to accomodate the factors in point.

Greg
 
Re: Expander Ball Effect on Brass Test

I should note that in Part II of this test (another post), that I did incur runout with use of the expander. And that expander was carbide, and also floats on the decapping pin, permitting it to find its own center within the neck. Until I get the gun to the range and test, I can't say what effect on accuracy any runout has. No doubt, dependent on the gun.

- Phil