Neck Expansion in Bottle-Neck Cases

[jmorris]

I have various processes depending like collet/mandrel, no expander at all (turned cases so wall thickness doesn’t throw in variables) either custom dies or interchangeable bushing dies, stand alone expander only die, expander on decapping pin steel and carbide.

As pointed out earlier measuring runout both before and after is the key to answering your question. As not all of them will give you the same results and what lube/how it’s applied can make the difference between good and bad results with the same tool as well.

 

[Toprudder]

The bushing die is all new to me so I am trying to understand the benefits. RCBS has both a full length bushing die for a 30-06 (14834) and a neck sizing bushing die for a 30-06 (14835) and I plan to try one of them. The headspace on a rifle is about .005 and I have tried to set the shoulder back .002 to see if that plan would allow the cartridges to be fired in more than one rifle. Even when fired in the same rifle it didn't work very well for me possibly due to springback of the shoulder or pulling on the shoulder by the expander ball. It looks like I could use the full length bushing die by removing the bushing to size only the body of the case, and then re-set the die above the shell holder and use the bushing to size only a portion of the neck. The un-sized portion of the neck would then center the round in the chamber. I have tried many things in the past, some with no benefit, and this may be one of them for me. Very interesting thread.

I have the Redding bushing die, it can do in one step what you describe. The bushing height can be adjusted independently of the shoulder, so you can full length size the body, bumping the shoulder as much as you want, and only size a portion of the neck.

 

[Mowgli Terry]

I was wondering an ordinary person could take a Lee FL die a modify. The does not have an expander ball. Would it be possible to take the spindle out of that die a polish it down to size your neck to the desired diameter. The brass could be neck sized and come out to the same diameter. I think there is instructions for doing basically the same modification to the collet sizing die several places on the net. Like keep it simple. This process is for ordinary shooters.

 

[Walkalong]

Would it be possible to take the spindle out of that die a polish it down to size your neck to the desired diameter.

Yes, and Lee might do it for you. I know Forster will hone a FL sizer neck to whatever you want, just match it to your brass. It's actually a great way to do it, but it is one size fits all vs being able to change bushings, you must continue to match the brass to it.

https://www.accurateshooter.com/technical-articles/reloading/fl-bushing-dies-vs-honed-fl-dies/

 

[labnoti]

Why expand at all? It might be needed if it's new brass and the neck diameter would put too much tension on the bullet, but I've not seen that. With brass expanded in the chamber, it only needs to be sized down to provide the correct neck tension.

I read the comments that sizing the OD only works if the necks are turned. Why? If the necks are not turned and I size the OD, the ID may not be concentric, but seating the bullet will do exactly the same thing as an ID sizing bead. Unless the necks are turned, there will never be perfect concentricity or uniform neck tension around the circumference of the neck. Suppose I did size the ID. Then I seated the bullet. Do I have consistent neck tension around the circumference? No, not if the neck thickness is inconsistent.

Turning the necks can provide more consistent neck tension around the circumference. ID sizing cannot. So turn the necks if you want to, but I can't see a point to ID sizing. Turned or not, just size the OD with the appropriate bushing for the desired neck tension, seat the bullet, and go.

 

[Slamfire]

I was wondering an ordinary person could take a Lee FL die a modify. The does not have an expander ball. Would it be possible to take the spindle out of that die a polish it down to size your neck to the desired diameter. The brass could be neck sized and come out to the same diameter. I think there is instructions for doing basically the same modification to the collet sizing die several places on the net. Like keep it simple. This process is for ordinary shooters.

As Walkalong said, Lee might reduce the spindle. But, what really work hardens the brass is the amount the die reduces the case neck before it goes back over the expander.

 

[Mowgli Terry]

There may variations in Lee conventional FL dies. The one I had in mind had no expander ball. The spindle, for lack of a better term, served as a mandrel that would resize the neck. Reduce the diameter of the spindle and the neck gets smaller in diameter. No doubt the expander ball damages the brass. In the example of RCBS it was possible to get several different sizes expander balls for asking for thirty caliber. I was loading lead bullets in 308. I changed over to Lee collet dies and the concern about expander balls went away. Lee is great for showing up with the better mouse trap.

Addendum: Back in the day we fiddled with all sorts of ways to prepare brass building accurate ammo. We decided that, with a standard chamber, you would get to the point of diminishing returns PDQ.YMMV

 

[jmorris]

Why expand at all? It might be needed if it's new brass and the neck diameter would put too much tension on the bullet, but I've not seen that. With brass expanded in the chamber, it only needs to be sized down to provide the correct neck tension.

I don’t neck expand at all for a couple of firearms. Why I don’t for all, is because you have to have a consistent wall thickness to size a given OD and have a particular ID. If you have different thickness neck walls and don’t expand you will have different ID’s. If you turn every case to the same wall thickness, and the necks don’t get any damage on them between firing and reloading, and size the OD correctly, you don’t need an expander.

Dents in case mouths also occur and OD, only can’t fire them, that’s where the expander comes in again.

 

[jmorris]

There may variations in Lee conventional FL dies. The one I had in mind had no expander ball. The spindle, for lack of a better term, served as a mandrel that would resize the neck.

These are from 3 different .30 cal Lee dies.

The collet die is the one that is just a mandrel the case is squeezed to, the center is a .300 win mag and the right is 300 blk.



FWIW, if you put that 300 WM decap/expander pin in a universal decap die, instead of the regular pistol pin, you would be getting very close to the Sinclair expanding die. As far as a push in expander vs pull out.

 

[armoredman]

I am a stupid amatuer and I have the Lee neck expander die. I use it on .223 brass so bullets seated don't shave on my chamfered case mouths. I never really measured, just went on feel to expand the neck " just a touch". Then I seat...and here comes the heresy - I use the Lee Factory Crimp Die "just a touch" to snug it back. Maybe I am doing it wrong, as nobody ever showed me how to reload anything, but it seems to work, especially with cast lead in .223. The ARs seem to like it.

 

[Mowgli Terry]

Maybe I am doing it wrong, as nobody ever showed me how to reload anything, but it seems to work, especially with cast lead in .223. The ARs seem to like it.

Your process is exactly what goes on here loading 308 with cast bullets. If there is a difference it's in my use of an NOE expander plug in the Lee Universal Expander.

 

[lightman]

I use the supplied expander ball most of the time. The exceptions are when I turn the case necks for my tight chambered rifles and when I load cast bullets in bottle neck cases. If I turn the necks I use a bushing neck die and do about like 243winxb does. If I'm loading cast bullets I still use the expander and follow with a Lyman "M" die.

I have replaced the expander balls with carbide expander balls on the cartridges that I load the most. I have also polished about every standard expander ball that I own. I use an electric drill and 1200 grit emory cloth for this.

 

[Toprudder]

I am a stupid amatuer and I have the Lee neck expander die. I use it on .223 brass so bullets seated don't shave on my chamfered case mouths. I never really measured, just went on feel to expand the neck " just a touch". Then I seat...and here comes the heresy - I use the Lee Factory Crimp Die "just a touch" to snug it back. Maybe I am doing it wrong, as nobody ever showed me how to reload anything, but it seems to work, especially with cast lead in .223. The ARs seem to like it.

Nothing at all wrong with that. I use the universal expander for similar reasons, when I am seating some flat based bullets. I also use the FCD for when I am making plinking ammo.

In my opinion, the Lee universal expander really isn't an "expander". It only flares the case mouth. The inside diameter must be expanded by other means.

 

[Mowgli Terry]

In my opinion, the Lee universal expander really isn't an "expander". It only flares the case mouth. The inside diameter must expanded by other means.

The Lee Universal Expander is great for what it was designed for. I don't think I have had much luck getting people to look at NOE's honest to God expanders that fit into the Universal Expander Die body. Check them out on the NOE website.

 

[Toprudder]

The Lee Universal Expander is great for what it was designed for. I don't think I have had much luck getting people to look at NOE's honest to God expanders that fit into the Universal Expander Die body. Check them out on the NOE website.

I agree that the Lee universal expander is great for what it was designed for, I just think it should be called "universal flare tool". I've got the 21st Century expanders, I'll have to check out the NOE expanders.

 

[armoredman]

I agree that the Lee universal expander is great for what it was designed for, I just think it should be called "universal flare tool". I've got the 21st Century expanders, I'll have to check out the NOE expanders.

I like it, great idea!

 

[Ireload2]

The drag is really no different. It only feels different because the linkage of the press does not have much mechanical advantage at the top of the ram stroke.

I'm curious as to how many folks rely on the 'button' in the typical sizing/decapping die to expand the necks of bottle-neck cases as opposed to not expanding during the sizing/ decapping process and then using a dedicated neck expanding die? I've gone to the latter since I feel it gives me a better quality neck expansion, allows me to only expand the amount of case neck needed for the given bullet I'm loading, and avoids that excessive drag I get with the typical sizing die button which I feel must be stretching the cases, even when I lube the inside of the case mouths. It does require an extra step, but I feel it is worth it. So, just wondering how many folks do the same.

 

[Hooda Thunkit]

...I don't think I have had much luck getting people to look at NOE's honest to God expanders that fit into the Universal Expander Die body. Check them out on the NOE website.

I use the NOE expanders. I think they are the best thing since sliced bread.

For instance, loading 7.62x54r for my Finn M39. The bore slugs at .3105, I size my home-cast projectiles at .311.
I turned the necks to .011 thick.
I neck size the brass using the Lee Collet neck size die for 308 Winchester, shimmed to use with the 7.62x54r.

That leaves the ID at .307. I use the NOE .309 x 312 expander, which gives me .002 tension. A slight kiss by the Lee Collet Crimp, and I'm done.

I shot a 285 - 8x (out of 300) last week at 100 yards, including a 97-2x, and a 97-4x.

 

[sage5907]

I have never used a bushing die and I got really interested when I read this thread so I ordered a RCBS 30-06 full length bushing die and I thought it would come with at least one bushing. I didn't realize that RCBS doesn't furnish a bushing with the die and it has to be purchased separately so now I am waiting for bushings with 333 and 334 diameters to arrive from Midway. Lesson learned.

I was curious as to the diameter of the new expander ball so I used a micrometer to measure the diameter of the expander and it was .308. That was a surprise to me because the expander from the die I have been using measures .307.