Sticky Expander Ball

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TX_Diver

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That’s a lot. A lot of everything. I always err on the side of a little more tension than the traditional .002, but that’s just to make sure there is always enough for odd brass.

For reference. My last 6.5 barrel, with lapua brass (thick necks) I was sizing with a .288 bushing and running a .262 mandrel through it. Moving the brass as little as I needed to provide .0025-.003 of neck tension.

Another issue I see happening that may help you is neck hardening if you do not anneal. This might make your problem worse, but also might yield a little larger neck diameter after sizing eventually.

The issues you’re seeing are 100% from factory dies designed to size all brass regardless of thickness. Unfortunately there’s not many ways around it.

Personally if I were you, and if you have a bucch of that brass, I’d just order a forester honed to your dimension on the neck and enjoy more consistent brass.

I've got 500 pieces. Not really looking to purchase an annealer or even new dies at this point although I'm sure it'd be helpful in the future.

If I'm understanding right I could also just send them my existing die and for $26 they'd open the neck up? https://www.forsterproducts.com/resources/custom-machining-service/

CUSTOM NECK HONING OF FORSTER FULL LENGTH SIZING DIE​

We custom-hone the inside neck diameter by using a diamond stoning process. We enlarge the inside diameter to your specification to prevent oversizing of the case neck due to thick neck walls. You may require this service for multiple reasons:

  1. If you use some brands of brass cases with thicker neck walls.
  2. If you do not intend to outside neck turn case necks that have thickened after repeated firings.
Please send us your die along with the Custom Neck Honing Form, specifying the inside neck diameter. Note:

  1. No more than .008″ stock removal from your existing die neck diameter is possible.
  2. Honing is done in increments of one-half thousandth of an inch (.0005″), meaning that your specified inside diameter must be either .XXX0″ or .XXX5″.
$26.00, includes shipping within continental U.S. (lower 48 states). Please allow 1-3 weeks.

Then I could effectively have them open the neck up to .287 or something and get back to .288 by using the expander?

If I don't have to buy a new die that's not a bad option for $26...
 
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TX_Diver

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May 27, 2019
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2,260
That’s a lot. A lot of everything. I always err on the side of a little more tension than the traditional .002, but that’s just to make sure there is always enough for odd brass.

For reference. My last 6.5 barrel, with lapua brass (thick necks) I was sizing with a .288 bushing and running a .262 mandrel through it. Moving the brass as little as I needed to provide .0025-.003 of neck tension.

Another issue I see happening that may help you is neck hardening if you do not anneal. This might make your problem worse, but also might yield a little larger neck diameter after sizing eventually.

The issues you’re seeing are 100% from factory dies designed to size all brass regardless of thickness. Unfortunately there’s not many ways around it.

Personally if I were you, and if you have a bucch of that brass, I’d just order a forester honed to your dimension on the neck and enjoy more consistent brass.

Alternately I could order a bushing die and use a .288 bushing with no expander ball?
 
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Not really for no other reason than I don't want to go buy new dies I guess...

Copy. You need to make sure each piece of brass is assigned to the rifle that shot it, too, which can be an extra step if you reload for multiple people.

The nice thing is neck sizing is much faster than FL and requires no lube. It also doesn’t work the brass near as much. Also I don’t need to trim as much or as often.




P
 

Lawnboi

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Alternately I could order a bushing die and use a .288 bushing with no expander ball?
I’m not a huge fan of a bushing die, atleast not a traditional one. You end up with a doughnut after a number of firings. Many use them successfully and they do work. Some don’t use an expander after.

Personally I size .004 under a loaded round diameter and expand it up with a mandrel in or out of the die. This does minimal work to the brass.

The forester honed sizers are well worth the price IMO, I use a SAC die for the creedmoor cartridges, which I’m sure you don’t want to spend, but the forester dies are economical and you can spec your neck diameter. I’d follow their directions on choosing a size. Another positive on the forester is you can adjust the ball up and down, so it expands a supported case as it comes out of the neck.

Unfortunately theres a lot of options with this.
 

sdupontjr

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Depending on the type of lube your using, I use a homemade lube of 99% alcohol and liquid lanolin. Every now and then, my RCBS FL dies do this. I pull the expander ball, wipe it down, put the die back together. then I squirt a little of teh lube inside the die. Let it dry 100% before trying to size brass. It lubes the expander ball. You will notice that it becomes slicker on the upstroke. Depending on how much carbon and soot you have inside the neck will cause this issue.
 
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I can’t believe people still use expander balls in lieu of a mandrel. The whole operation is smoother and works the brass less than an expander ball.

Annealing isn’t a bad idea considering how much you are working the brass and shoulder on that setup. .012” is a LOT to work the brass. You are also likely removing some of the shoulder bump trying to pull the expander ball back through.

If you just don’t want to buy a new die that uses bushings, I would have your die neck honed and do final sizing with a universal mandrel die and the appropriate expander mandrel.


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Vern400

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Aug 22, 2021
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I've had that happen.

I took out the expander ball and spun it with a electric drill and rubbed a scotchbrite pad on it to clean and polish it. It won't remove enough material to be an issue. I'm pretty sure it was just gooped up and it did have some brass residue on it.

Second, I started using imperial die wax

If You Yoink on your brass too hard on the up stroke you can cause the neck to be not concentric with the bore which will mess up your accuracy.
 
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TX_Diver

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As an update I ended up ordering a Forster die and will send it to them to be honed. Thanks @Lawnboi for the heads up that was even an option. Will be about $90 all in with the die from midway, shipping it to them, and getting the service done. Will update again in a few weeks when I have it back.

FL redding sizing die (6.5 creedmoor) for sale if anyone wants one. I bought the set and sold the seater to use a forster micrometer. Now I'm selling the sizer lol...
 

Lawnboi

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As an update I ended up ordering a Forster die and will send it to them to be honed. Thanks @Lawnboi for the heads up that was even an option. Will be about $90 all in with the die from midway, shipping it to them, and getting the service done. Will update again in a few weeks when I have it back.

FL redding sizing die (6.5 creedmoor) for sale if anyone wants one. I bought the set and sold the seater to use a forster micrometer. Now I'm selling the sizer lol...
Clean it out good before using it. I think you will be happy with it.
 

Vern400

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Try pulling the expander out, size a case and seat a bullet. If the bullet seats fine without feeling like you are smashing the hell out of it, leave the expander out forever. If the dies require the expander to hold the decapping pin, swap in an undersize expander. This is what I do in a lot of die sets.

Some brass also have thicker necks than other brands. Not sure if this is how Starline is in the Creed. Did you change brass makes in the meantime?

Jeremy
I agree your proposal will work. The undersized expander ball is a far superior idea that you had. The sizing die forces the OD of the cartridge into its dimension. So all the run out in the case thickness goes to the ID. Depending on what you're doing with the cartridges it may not matter but that approach of not using the expander ball at all would cause the highest theoretical variation in the interference fit. When we force an expander Ball even if it's undersize, through the neck at the upstroke, we're establishing the ID of the case as the datum, and letting the wall variation go toward the outside. Then we hope we've got a chamber that'll handle the case thickness.

I learned something new. I didn't know they were undersize expander balls.
 
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