Expander ball - who needs that thing?

orchemo · Jan 12, 2012

I received several suggestions regarding my question about sticky expander ball extraction. The responses ranged from
1. lube inside of case
2. polish the expander ball
3. remove the expander ball

First two I get and am now doing that. What about removing the expander ball or just using one of a smaller size to enable de-priming.

If I am using boat tail bullets, do I need the expander ball? Just curious.

Cheers

joelkdouglas · Jan 12, 2012

Orchemo,

I removed the Expander Ball from my sizing die. I actually took the entire rod off.

I use a Lee Universal Depriming and Decapping Die, $11.99 from MidwayUSA, to deprime the cases, so I don't need the expander rod for that.

I believe if you use regular dies you need the expander ball, but I don't know why. I've never used regular dies. I understand if you use either Lee Collet Dies or Redding S-Type Bushing Dies you can remove the expander ball. I use the Redding S-Type dies.

For the Redding Dies, here's a disclaimer. If you have brass with uneven neck thickness and you haven't used an expander ball, the outside of the neck will be the same diameter, but the inside will not. Reportedly this results in different pressure on the bullet and can result in poor accuracy.

I use the Redding Dies without an expander ball and don't have a concentricity gauge for the neck thickness and get slightly sub-MOA accuracy, but I use Lapua or Nosler brass. I believe if I were to switch to Rem or Win brass I would need to get a concentricity gauge and sort my brass for thickness, eliminating pieces that varied throughout the neck.

I should probably get a concentricity gauge for my Lapua brass even, but I don't have a problem with my group sizes typically, so I figure it's probably a waste of money.

I'm no expert though. Most of this I've learned from more experienced reloaders and their posts. I just neck size primarily, prime, charge, put the bullet in, and go shoot.

joelkdouglas · Jan 12, 2012

I just read your initial post too, about 25-06 brass.

Are you sizing from 30-06 brass? If so, Redding mentions you need to step down in sizes if using the S-type Dies to get to the correct neck diameter. I don't know anything about sizing from 30-06 to 25-06, though, as I shoot only a 30-06.

woods · Jan 12, 2012

Whether you should just remove the expander ball from your full length die and get good results depend upon a few things. See the interior of the full length die is made where the neck is very concentric with the case body. So when you remove the expander ball and stem and run the case up into the die it will size the case and leave the case neck and case body very much aligned with low runout. But like joel said, you have to worry about the variances in neck thickness being moved to the inside diameter of the neck. Also you need to worry about the ID being smaller than usual (no expander ball to re-expand the neck to the proper diameter) which will cause a higher bullet seating force and that may cause other problems such as re-introducing runout.

So the only way to tell is to remove the expander ball and size a case. Then measure the outside diameter of the sized case and a loaded round.

For example (since someone mentioned a 25-06) if your OD of a loaded round is .285" then you know your neck brass thickness is .014" per side

.285"-.257" (bullet diameter)=.028"/2=.014"

Now if you size a case without the expander and the OD of the sized but unloaded case is .279" then the ID of the neck will be .251"

.279"-.028" (both sides brass thickness as previously determined)=.251"

that would mean that your bullet would have to expand the neck .006" when seating

.257"-.251"=.006"

that is a little much and may cause concentricity problems and runout

But you can alleviate the problem by reducing the neck thickness with outside neck turning. In this example if you turned the necks down to .012" per side then you could reduce the ID to .255" and only have a bullet grip of .002" which is just right for a seating pressure that will not cause runout.

I have tested a few full length dies without the expander and have found one to work perfectly without even outside neck turning but most size too much and the brass neck is not thick enough to allow the math to work without outside neck turning below .010" per side which is a no-no

Easier to just buy a Lee Collet, get a better die, get rid of your concentricity problems and size without lube in the neck.

Guy Miner · Jan 13, 2012

There are some dies that do not use an expander ball. I reserve those bushing type dies for only a few of my rifles.

For the others, a tiny bit of lube inside the neck works wonders, using standard dies with an expander ball. Keeps it simple, and works fine.

RiverRider · Jan 13, 2012

I have operated with ordinary FL dies with the expander removed and I can't say it hurt OR helped anything at all one way or another---except for the reduced effort when sizing. Nowadays I dip the case neck in graphite and run the case mouth over a nylon brush during the resizing process, and it does reduce the effort required to extract the case from the sizing die.