Removed expander ball - Nk tension is way up!

[Wheres-Waldo]

I removed my expander ball in my Redding Type S FL Bushing die in an effort to reduce run out and increase consistency in the necks, which it has.

I'm using a .269" bushing (6mmCM Peterson SRP) and had, with the expander ball INSTALLED, been getting .002" tension; sized brass would read .272" and loaded rounds would read .274"

Since removing the expander and just sizing the exterior with the .269" bushing, they come out at .269"... And loaded rounds are still at .274"

I went from .002" to .005" neck tension, and I see why...

I'm going to shoot a double handful over the chronograph, but I expect an increase in velocity, as well as a wider ES & SD, and a decrease in accuracy, despite the ammo being straighter. And I guess I'll be ordering a .272" bushing!

May I pose a question here.
What's the point of a bushing in a die with an expander ball, which determines the final diameter of the neck and not the bushing?
I could always feel the expander ball in the necks on the downstroke of sizing, which I guess means the expander had the final say on neck tension, not the bushing... This doesn't make sense though, as a bushing is supposed to control neck tension, not the expander.

 

[Supersubes]

Fixed neck dies are one size fits all. Thick or thin neck brass all gets worked too much. Choose your bushing appropriately, and you minimize the amount of sizing needed. Expander balls push defects to the outside. Running a bushing only makes the OD round, but if your neck thickness varies, or is thicker or thinner than the last case, the ID with be neither round nor uniform in size. Imagine dragging an expander ball through two necks, one which is thicker than the other by .001. The ID will be virtually identical. If you just used a bushing, the thick necked case will have a .001 smaller ID. That’s no bueno. If your expander ball is garbage like most are, remove it, but you still should stick something down the neck, which is why the use of mandrels became so popular. Hornady expander balls are very nicely shaped, and in the their match dies, screw to a floating rod. Good design, and reasonably priced.


Edit: If your brass is very inform or sorted to be uniform, or neck turned, you can use just a bushing, many do. If you don’t want to do the sorting or neck turning, use a ball and be happy.

 

[dustingaunder]

I use the carbide floating expander ball from Redding and choose a bushing that’s the ball barely drags going out. No runout for me and nice round necks. No expander and any dented necks don’t get fixed by the bushing alone. The ball is sized to give you .002 neck tension no matter what bushing you use or how thick the brass is.

 

[straightshooter1]

I removed my expander ball in my Redding Type S FL Bushing die in an effort to reduce run out and increase consistency in the necks, which it has.

I'm using a .269" bushing (6mmCM Peterson SRP) and had, with the expander ball INSTALLED, been getting .002" tension; sized brass would read .272" and loaded rounds would read .274"

Since removing the expander and just sizing the exterior with the .269" bushing, they come out at .269"... And loaded rounds are still at .274"

I went from .002" to .005" neck tension, and I see why...

I'm going to shoot a double handful over the chronograph, but I expect an increase in velocity, as well as a wider ES & SD, and a decrease in accuracy, despite the ammo being straighter. And I guess I'll be ordering a .272" bushing!

May I pose a question here.
What's the point of a bushing in a die with an expander ball, which determines the final diameter of the neck and not the bushing?
I could always feel the expander ball in the necks on the downstroke of sizing, which I guess means the expander had the final say on neck tension, not the bushing... This doesn't make sense though, as a bushing is supposed to control neck tension, not the expander.

So, you've had a difference of .003 between having and not having the expander ball.

Without the expander ball the neck is being compressed, which is not only adding to it's length, it's making the neck thickness thicker. . . substantially depending on how far the bushing is taking the neck down. So, with a thicker neck using the same bushing, you're going to get more neck tension. Even running an expander mandrel only through the neck will not return the neck thickness back to where it was (though it's WILL reduce the thickness some from the stretching). With the expander ball left in, it will take that thicker neck from compression and put the neck thickness back to it's spec that designed into the die.

Did you also notice a difference in the length of the case? Without the expander ball, I'm sure you'll find that the case length did not grow as much as it did when using the expander ball.

When you use a bushing die, the bushing is somewhat free floating (supposed to self align with the neck) and in doing so, it seldom aligns the neck's axis with the case's axis. This is why one will tend to find more run out using a bushing die than those without. To get zero bullet runout, one needs to perfectly align the neck's inside diameter axis with the case's outside diameter axis. The busing will create a uniform outside diameter, but the inside diameter will not be so due to neck thickness variances and will not bring the two axes in alignment to get what many want in terms of runout. With either neck wall variances or misaligned axes or both, will result in runout issues.

Using a bushing die, it's easy enough to control neck tension with or without the expander ball . . . just need to use the appropriate size bushing. One is just not going to get the same results in neck tension using the same busing with and without the expander ball.

 

[427Cobra]

I too use the Redding floating expander ball, with a busing that allows the ball to barely touch on the way out, but I know think an expander mandrel is a better choice, and cheaper with the same or better results

 

[Wheres-Waldo]

I'm just going to put the expander ball back in and keep doing what I was always doing.

The ammo shoots fine. I'll be at the range : )

 

[Cascade Hemi]

Forster makes custom sized expander balls and will hone their dies to your specified size.

 

[Lunchbox27]

Ditch the expander.

I use bushing dies with a bushing 4 thousands under the neck tension I am after. After they are resized, I run them through a mandrel using a 21st Century neck turning arbor. This brings my neck tension to 2 thousands of my loaded round and ensures the neck is concentric.

This way is very consistent, only requires buying 1 die, then an arbor for each caliber ($19 for TiN), and finally helped reduce my ES down to low teens.

 

[Sixfivesavage]

Ditch the expander.

I use bushing dies with a bushing 4 thousands under the neck tension I am after. After they are resized, I run them through a mandrel using a 21st Century neck turning arbor. This brings my neck tension to 2 thousands of my loaded round and ensures the neck is concentric.

This way is very consistent, only requires buying 1 die, then an arbor for each caliber ($19 for TiN), and finally helped reduce my ES down to low teens.

Bingo.

 

[C.R. Adams]

something isn't jiving.

With the expander ball, you were getting the correct neck tension? Excluding any spring back, this suggests the expander ball is .002" under the bullet diameter AND that your neck bushing is sizing the brass to less than .002" the bullet diameter................... fired case goes in, glides over expander ball, neck bushing sizes neck down, then on the way out, the ball is opening it up to the correct diameter giving you the .002" neck tension.................... This is also supported by the statement of with the neck sizing bushing only, that you are ending up with .009" tension.

So either your brass is much thicker than you believe it to be and the .269" bushing is sizing the ID of the neck down to .235 (.243-.009=.235)........... this means your brass thickness is (.269-.235)/2=.017"............ .017" is .002" thicker than any lapua brass i have on hand (.308, .30-06, and 6.5 CR - roughly measured with calipers and NOT a tube mic. ) Hornady brass is measuring ~.014", so .017-.014=.003

.017*2+.243=.277 OD neck diameter............ .277-.269=.008." neck tension. So that is damn close to your .009" and allow for spring back here and there and maybe you get the .009"

So bottom line is, with the correct neck bushing a person should not need the expander ball. In fact, I'd recommend not using it, but that's neither here not there. So IMHO, I believe either your neck thickness is thicker than you believe it to be, ................................

OR the neck bushing actually a .264? ..... 4s and 9s often look similar........... go with the more likely case thickness of .015"...............0.015*2+.243-.264=.009"................ this also jives with the expander ball providing .002" neck tension and an undersized neck bushing scenario.

 

[Wheres-Waldo]

Your .009” is incorrect, I was at .005”

It’s certainly a .269”, it’s printed that and I verified it with pin gauges.

My Peterson necks are measuring consistently .0145” - .0155” which ads up... (.243) + (.0155 x 2) = .274

This evening I collected all my brass and ran it through with the expander and the .269” bushing. Every one comes out at .272”, and pretty decent looking on the concentricity gauge too! I checked 30 out of 148, anywhere from .00025” to .002”, that I can live with.
So as of now, .002” neck tension... ?

I did get better run-out on average with just a bushing, and an appropriate sized bushing would have me squared away, but what I have seems to be working and it’s me who can’t leave well enough alone.

I’m also at the stage where the less dicking around at the reloading bench, the better. The less steps to get ammo that shoots good enough, the better.
If I can load ammo in a few steps that will shoot 1/2-5/8MOA and I can neglect cleaning my rifle and it still runs like a top, Ima do it.

Im sure using a neck mandrel and or turning necks would net me less wiggle on the test indicator & I have a full K&M kit to do it, but until I have issues with accuracy, I think I need to focus on range time & not reloading time.

 

[C.R. Adams]

Your .009” is incorrect, I was at .005”

It’s certainly a .269”, it’s printed that and I verified it with pin gauges.

My Peterson necks are measuring consistently .0145” - .0155” which ads up... (.243) + (.0155 x 2) = .274

This evening I collected all my brass and ran it through with the expander and the .269” bushing. Every one comes out at .272”, and pretty decent looking on the concentricity gauge too! I checked 30 out of 148, anywhere from .00025” to .002”, that I can live with.
So as of now, .002” neck tension... ?

I did get better run-out on average with just a bushing, and an appropriate sized bushing would have me squared away, but what I have seems to be working and it’s me who can’t leave well enough alone.

I’m also at the stage where the less dicking around at the reloading bench, the better. The less steps to get ammo that shoots good enough, the better.
If I can load ammo in a few steps that will shoot 1/2-5/8MOA and I can neglect cleaning my rifle and it still runs like a top, Ima do it.

Im sure using a neck mandrel and or turning necks would net me less wiggle on the test indicator & I have a full K&M kit to do it, but until I have issues with accuracy, I think I need to focus on range time & not reloading time.

fuck me............ that whole time i read .009