Uniform neck tension - Bushing or expander ball?

[thefitter]

This question comes from 2 other threads. Which process provides more consistent and uniform neck tension? A bushing or an expander ball? Thanks

 

[jmatters]

I think it's the wrong question. The question should be which one yields better shooting brass. The answer is bushing and NO expander. (IMHO)

 

[308sako]

I find that Reddings prescribed method of using the expander ball gives me a more uniform neck tension. However, by keeping lots of brass segregated and annealing frequently the bushing only method seems to produce superior on target results. I therefore think it is a matter of preference and technique which the individual loader must try to learn for himself.

 

[Heavies]

Other than the inability of the Lee collet neck sizer to change/play with neck tension, (without permanently modifying the center mandrel) I feel, this is the best way to get the most consistent tension, and low runout.
The way the die works, IMHO, makes the most sense in consistent sizing and tension.
Due to cheap manufacture, sometimes quality in the machining is lacking. However, in the three calibers that I have used them, they have worked superbly.
Too bad Lee doesn't make extra mandrels in .001 increments.
That would be the best!

 

[artbosco]

Which process provides more consistent and uniform neck tension? A bushing or an expander ball?

A carbide neck bushing!

Hard to find but available from:

Bud Mundy, Director, NBRSA Mississippi Valley Region
5956 Old Hickory Trail
Hillsboro, MO 63050-3231
Cell Phone 314-805-1313

 

[RonAKA]

This question comes from 2 other threads. Which process provides more consistent and uniform neck tension? A bushing or an expander ball? Thanks

I would suggest the expander ball gives a more uniform neck tension. The reason is that you are controlling the size of the ID directly. A bushing only sizer can only control outside diameter, and depends on neck brass thickness uniformity to get a uniform ID. If you neck turn your brass, or next best to that, use Lapua brass then neck thickness is probably going to be quite uniform. That said, the ID is still likely to be more uniform with the expander ball.

The knock on the expander ball is that it causes eccentricity of the neck. I think there are two reasons for that. First in a normal sizing die (neck or FL), the neck is sized down to a quite a bit undersized, and then sized back up again quite a bit to the final size. Combine that with a factory chamber that makes the fired brass neck start out quite large, and you have a lot of working of the brass in the neck. It causes it to crack sooner, and also causes eccentricity.

The second reason is the way most dies are made. RCBS, Redding, and others put their expander ball down low in the die so the ball passes through the neck when the case is not well supported. This can pull the neck off centre. Forster puts the expander ball high up in the die so the expander starts into the neck while the neck is still supported in the sizer. This tends to minimize any eccentricity effect.

I think you can have the best of both worlds if you use a bushing die (or honed out FL die) to just size the brass down to slightly smaller than final size, and then pass the expander through last to bring it back up to the final. I use that method and the expander ball only opens the neck up about 0.0003". I feel that is not enough to cause any eccentricity while still making the neck ID uniform.

Not a popular idea, but I use it...

 

[artbosco]

This question comes from 2 other threads. Which process provides more consistent and uniform neck tension? A bushing or an expander ball? Thanks

I think you can have the best of both worlds if you use a bushing die (or honed out FL die) to just size the brass down to slightly smaller than final size, and then pass the expander through last to bring it back up to the final.

Passing an expander ball through a case neck that's been run through a bushing die TOTALLY defeats the purpose of the bushing. That why you'll never see an expander ball on a custom made Bushing Die.

Harrell's Dies are a perfect example: http://harrellsprec.com/index.php?crn=207&rn=384&action=show_detail Their dies size to the tension or dimension the bushing was designed for. No additional manipulation required for the final size.

 

[bozo699]

This question comes from 2 other threads. Which process provides more consistent and uniform neck tension? A bushing or an expander ball? Thanks

I would suggest the expander ball gives a more uniform neck tension. The reason is that you are controlling the size of the ID directly. A bushing only sizer can only control outside diameter, and depends on neck brass thickness uniformity to get a uniform ID. If you neck turn your brass, or next best to that, use Lapua brass then neck thickness is probably going to be quite uniform. That said, the ID is still likely to be more uniform with the expander ball.

The knock on the expander ball is that it causes eccentricity of the neck. I think there are two reasons for that. First in a normal sizing die (neck or FL), the neck is sized down to a quite a bit undersized, and then sized back up again quite a bit to the final size. Combine that with a factory chamber that makes the fired brass neck start out quite large, and you have a lot of working of the brass in the neck. It causes it to crack sooner, and also causes eccentricity.

The second reason is the way most dies are made. RCBS, Redding, and others put their expander ball down low in the die so the ball passes through the neck when the case is not well supported. This can pull the neck off centre. Forster puts the expander ball high up in the die so the expander starts into the neck while the neck is still supported in the sizer. This tends to minimize any eccentricity effect.

I think you can have the best of both worlds if you use a bushing die (or honed out FL die) to just size the brass down to slightly smaller than final size, and then pass the expander through last to bring it back up to the final. I use that method and the expander ball only opens the neck up about 0.0003". I feel that is not enough to cause any eccentricity while still making the neck ID uniform.

Not a popular idea, but I use it...

Ron,
I would have argued with you on this a couple of weeks ago, but after the help (lesson) you and X500 gave me I am starting to come around to a different way of thinking.

Boys, I usually turn the necks on all my brass except some of my close range hunting rifles and have converted to mostly all bushing dies, on my competition guns the runout was small but on my hunting and Varmint rifles the runout was terrible I had taken a dislike to bushing dies because my standard dies w/expander balls produced more eccentric cases I had tried everything I could think of and was getting to the end of my rope with it. Then I bought a 6.284 longrange BR rig and the runout on my neck turned Lapua brass was so bad, (up to .007)
I did come to the end of my rope I was ready to take a hammer and start smashing things and kicking and scream like a little baby, I had completely had it!! I wrote a new thread, something on the lines of HELP!! first post was X500 wanted to know how much was I sizing my necks @ at once ( who care I have concentric problems) well I measured my fired brass and my re sized brass so I could give a accurate answer ??? my chamber was .282, my sized brass was .270, he replied back to size it in several steps, not more than .002 or .003 at a time. Then Ron chimed in with some more info on the same lines as X500s and of course a expander ball, I tried there suggestions and ended up with less than .002-.003 runout then I tried something else, I sized half the neck then rotated case 180 deg and finished sizing and dropped it to .001-.002 I think if you have a tight chamber and concentric brass I think you can do fine with sizing with a bushing only. But if your having to size your brass more than .002 or .003 I think maybe you would be better off with a expander ball. I have since had my reamer reground to .272 and re chambered the rifle, unturned 6.5*284 Lapua necked down to 6.284 then loaded runs about .272-.273 so I had to turn .0015 off the brass, after I fireform the brass it comes out of the chamber with a .271 od neck and less than .0003 runout I resize with a bushing n/k die and no expander then bump the shoulder .001 with the body die and my loaded round @ the ogive is usually under .005 runout .
I know I was long winded but I wanted to share my uniform neck tension and concentric problems I was having and how RonAKA and X500 really helped me with just 3 or 4 post replies to my question and ron made me relize that expander ball weren't always VOODOO!! I still won't use them if I am not having any problems but if I am or I have a known loose chamber I wont hesitate to put it back in.
Wayne.

 

[lurcher]

Too bad Lee doesn't make extra mandrels in .001 increments.
That would be the best!

They do. you need to contact Lee directly and make an order. I got them to make me mandrels 0.001 and 0.002 under

 

[necchi]

Ron made a good point about Foster dies haveing the expander high in the die.
There's no rule that states you have to leave the expander in it's factory position with ANY die.
I de-cap with a Lee Universal simply because I don't want to beat my sizing dies up with dirty brass.
(and it's cheap)
I have RCBS and Redding dies. With my RCBS I was having concentricity issues until I moved the exander way up in the die and placed a small rubber O-ring under the expander rod lock nut. The O-ring let's the expander float instead of being tightened at a possible angle because of the threads.
I'm getting neck run-out of .001 or less now, very happy. Neck tension is running .002-.003. If I have problem cases they are sorted out and I outside turn the necks.
These are factory Hunting guns not BR. I'm lucky enough (knock on wood) to have good concentric chambers on these guns, the chambers and neck are typical big, but fired rounds come out straight.

 

[spclark]

I stopped using an expander because of the additional, vertical stress on the shoulder and neck metal when the expander's drawn upwards thru a reduced ID neck.

To me it just seems more "logical" to use a bushing die that leaves necks at the right ID (or perhaps just slightly smaller, then use an expander to even them out & size them to hold a bullet) in one operation.

If I'm going to turn necks I use a smaller bushing, then an expander mandrel to get the best fit on the turner.

Maybe for hunting loads expander balls are OK but for my competition shooting I'd rather do it my way & have confidence in my loads when I leave home for the weekend.

 

[BoydAllen]

FYI when using a bushing FL die with unturned case necks, an expander can actually do some good, and not cause problems, as long as a bushing is selected that only has the expander ball doing a slight amount of work. The reason that expander balls can cause problems is because necks are often sized to such a small diameter that when the expander is pulled back through them, the pull on the shoulder is enough to cause it to yield, which it generally does unevenly, causing the neck to be cocked relative to the CL of the case body. With the right bushing selection, this does not take place, and the ID of unturned case necks, and neck tension can be made more uniform than they would be without the expander.

 

[RonAKA]

I think the devil is in the detail on this one. There is no simple black and white answer. Yes, if you stretch the crap out of your neck with an expander ball, they are going to do bad things. It may just be my twisted logic, but my thoughts are that if all the expander ball does is open up the ID by 0.0003" for example to make it uniform, then not much bad could happen. In fact if one took the extreme and all that 0.0003" went to one side of the neck, then the very worst it could do is increase runout by 0.0003" which is not really significant. I strongly suspect that this possible worst case and the actual case is much better.

Totally different ball game though if you are expanding the neck ID by 0.003" or 10 times that amount.

 

[moosetracker]

Other than the inability of the Lee collet neck sizer to change/play with neck tension, (without permanently modifying the center mandrel) I feel, this is the best way to get the most consistent tension, and low runout.
The way the die works, IMHO, makes the most sense in consistent sizing and tension.
Due to cheap manufacture, sometimes quality in the machining is lacking. However, in the three calibers that I have used them, they have worked superbly.
Too bad Lee doesn't make extra mandrels in .001 increments.
That would be the best!

+1 on the Lee Collet die. I prefer that to any other, including bushing types.

BTW, you can get custom mandrels from Lee for about $5 each.

 

[KevinThomas]

I would suggest the expander ball gives a more uniform neck tension. The reason is that you are controlling the size of the ID directly. A bushing only sizer can only control outside diameter, and depends on neck brass thickness uniformity to get a uniform ID.
[/quote]

With you 100% on this Ron. This is what I've been doing for years for most of my own reloading. I use the bushings, but size them to the point where the carbide expander ball barely kisses the inside of the neck when it passes through. Not much, but I do want ti to touch, just to ensure that uniformity. This isn't a one size fits all issue, and fro some types of reloading, this may not be the wway to go. For my own Service and Match Rifle reloading, however, this is what I've found works best.

 

[Laurie]

While I agree with Ron and Kevin 100%, there is also an alternative to the traditional expander ball, a mandrel. I use my Sinclair neck-turning expander die and appropriate calibre 'E' mandrel on most of my cartridges. It is a less stressful method than drawing the case over a 'ball' taking much less effort on the press handle. You do still need to lube the inside case-neck walls, though.

 

[Heavies]

When you are yanking the expander ball or mandrel in and out of the neck there is always a chance to mess up the neck. That is why I suggest the collet neck die. There is no forcing of metal through a thin tube that will deform, sooner or later, no matter what type of lube you put in there. The collet die squeezes the neck around a fixed floating mandrel, thus self centering and creating minimal runout.

No lube is necessary, and you cannot go any smaller or larger that the center post will allow. You can size down most any sloppy factory necks with out fear, and you are not required to size in steps. You could get custom mandrels if you want to play with neck tension, as moosetracker and lurcher suggests. The ID is as consistent as the mandrel is, no matter what, and any neck irregularities are forced to the exterior of the neck where it will be less of an issue.

Use your Bump Die with out any bushing or ball to bump the shoulder when necessary (I use a redding body die), then neck size it.
You can even stick a flat washer under the die when you neck size to leave a little bump at the base of the neck, to get things lined up with the bore!

With a factory chamber, or a no turn neck chamber, this is your best bet.

It cannot get any easier than that!

 

[KevinThomas]

Hi Laurie,

agreed on the mandrel completely, but that does add another step. I use them frequently for a number of chores, but the correctly sized bushing in conjuntion with the expander ball saves some time. Matters when we're doing up a couple thousand match rounds for the upcoming season!

Haven't been by in a while, but did you get a chance to read Misfire?

 

[Laurie]

Haven't been by in a while, but did you get a chance to read Misfire?

Kevin,

yes my secondhand copy arrived from the USA three or four weeks ago and I promptly read the later sections from the Krag onwards almost unable to put the book down! Very entertaining and informative.

I'll have to go back and read the earlier chapters now. Meanwhile, we're wasting more money than ever over here - Nimrod Early Warning aircraft being broken up before they make their maiden flight, our sole mini-carrier (HMS Ark Royal) and her Harrier VTOL aircraft being decommissioned while we go ahead with building two large carriers (but WITHOUT any aircraft as we can't afford them) because "it would be more expensive to cancel them", so no sea-based air support for 10 years in all probability. We no sooner do this than North Africa / the Middle East become unstable and we're struggling to extract our oil workers from Libya. (Oh yes and the Prime Minister announces he's leading the world in enforcing a no-fly zone over Libya, only it turns out we have no air power to enforce it even if your Prez, Hizzoner Vlad Putin and the Chinese had supported this initiative, which they haven't!)

I could go on, but I'd just depress myself. I thought things couldn't get worse than under Gordon Brown and Labour, but they have. Wasting millions on the SA80 rifle and similar seems quite inconsequential now. Somebody will write a history in a few years about how Europe managed to ruin itself and throw away 1,000 years of experience, culture, history, success etc in a generation thanks to the stupidity of its leaders and 'important people', unless the masses revolt soon. I keep telling my offspring to emigrate before it's too late, but they think I'm kidding!

On the mandrel, yes another step and I can see why it wouldn't suit if you load for XC or other high ammo expenditure disciplines. By chance, I found that Sinclair's E-mandrels seemed to give very consistent results on cases on their first firing after a clean-up neck-turn. This is a particular boon with my long-range (800yd +) .223R/90 ammo where getting the MV ES value down is a challenge. After sizing with a Forster Bushing-Bump die and a 0.002" undersize bushing, I run the cases through the mandrel. With Berger 90gn VLDs around 15 thou' into the rifling, it seems to be just a nice amount of grip and the pressure needed on the Redding T7 handle during seating seems very consistent.

Now there's a question for Lapua Nammo Oy - any chance of 80 and 90gn 0.224" Scenars? We're relying on only two bullets for workable 90s, both from Berger, and supply can be iffy over here. I just bought another 1,000 VLDs from the main UK importer at our main annual gun show last weekend to ensure I have two or three seasons worth on hand. Ecven with my fondness for Scenars I know I can't expect Lapua to supply 90s for a limited market demand, but a nicely made 80 or 82 for 1-8" twist would be nice. I've tried the 77s and found they shot very well for shorter ranges.

 

[bozo699]

Laurie,
I see your blood pressure is high enough to blow a vessel,...mine too! Remember Liberalism is running rampant in your goverment and my goverment as well, so if you don't want to have a stroke stop thinking about it and have nice thoughts like getting a 2" group @ 800+ yards with your .223
Wayne.