Mandrel vs Expander button in a die

[Mr Underbridge]

I am reexamining some of my reloading practices. I am sure this was asked a lot.
If I have whidden bushing dies with a set of custom sized expander buttons will this combo perform same/similar enough to mandrel and bushing combo?
I know that on a generic dies those expander buttons really work the neck over but on whidden die i can match my neck wall thickness with right bushing size and right expander button diameter.
Thanks

 

[Hohn]

Nobody has responded because nobody can really answer this. It depends on your brass, your bushing ID, your expander OD, etc.

The less you work the neck, the less difference you will see between processes.

Is there a reason you think you need an expander after sizing? The whole point of the expander is that the dies must be made too small so they can size any and all brass thickness in a caliber. If you have a bushing, you can size only enough to get the ID you need for your brass.

The Wilson FL bushing sizing die doesn’t have an expander for this reason.

 

[Mr Underbridge]

Just to make sure that any imperfections get pushed to the outside even though i did turn my necks. My 308 win brass is about on its 12th reload and i figured I better make sure that the surface where the bullet and the brass mate is straight.

 

[INTJ]

Just to make sure that any imperfections get pushed to the outside even though i did turn my necks. My 308 win brass is about on its 12th reload and i figured I better make sure that the surface where the bullet and the brass mate is straight.

This ^^^^

When I use the proper size expander, my seating pressure is much more consistent--as measured on my 21st Century Hydro Seater press.

 

[Uncle Ed]

The Redding bushing die FAQ tells you if the neck thickness varies .002 or more to use the expander that comes with their die.

The purpose of a normal dies expander is to size the inside of the neck back up to .001 or .002 smaller than bullet diameter.

The dies neck diameter and thickness of the case neck determines how much the case neck is worked.

One problem when using an expander is when it is locked down off center and induces neck runout.

And if you neck turn with a bushing die you should not need to use a expander.

And if you neck turn in a standard SAAMI factory chamber the neck will expand more when fired and be worked more when sized.

Below I replaced the expander on my .243 Redding full length die with a high mounted Forster expander to reduce neck runout. A rubber o-ring is under the expanders lock ring allowing the expander to float and self center.

Bottom line, simply checking the sized case neck on a runout gauge will tell you if the expander is pulling the necks off center.

Below a Forster non-bushing full length die produces less neck runout than a Redding bushing die.

 

[INTJ]

Yes in THEORY neck-turned cases shouldn't need an expander. However, over several hundred rounds I have seen how using an expander mandrel results results in much more consistent seating pressure, as measured on a hydro seater, even with neck turned cases.

 

[Mr Underbridge]

So for best results it seems I should use a custom honed dies without a button followed by an expander / mandrel as the last step?

 

[INTJ]

So for best results it seems I should use a custom honed dies without a button followed by an expander / mandrel as the last step?

In the 26 years since I became "serious" about reloading I have only had one die that made necks crooked. I almost always use expander buttons.

When I came back to LR/BR in 2018 I initially didn't use an expander in the die. However, I found the expander made seating much smoother and yielded a more consistent seating PSI.

I am using custom Whidden bushing dies with Whidden expanders for sizing and seating with Wilson inline dies on a Century 21 Hydro Seater press. I don't even check runout anymore.

I know many others who get excellent results and use only a bushing, so there is no one right answer to what's best. You have to experiment and find what works best for you.

 

[Sniper338]

I use a redding FL bushing die, then run over an expander mandrel.

In the end theres several ways to skin a cat. Depends what works best for you.

 

[D-4297]

I use a Redding F/L Bushing Die with the Button removed from the stem , followed by a .3075 21st Century expander mandrel . For me ; I had to find the right bushing that would close my neck I.D. down no more than .3065 - .3070 , thus reducing the amount of moving the brass around . I shoot a No-turn chamber , and after the second or third reload , the brass is very consistent , thickness-wise , according to my Mititoyo tube mic . I do anneal after every firing , too .

 

[Uncle Ed]

So for best results it seems I should use a custom honed dies without a button followed by an expander / mandrel as the last step?

I have Forster dies for every rifle I own and none of them have honed necks. And all my rifles are off the shelf factory rifles with SAAMI chambers. I did not have the necks honed so that I can use any brand of brass and in my opinion these dies do not over work the necks.

There is no sense in owning a Forster die if you plan on removing the expander and not using it. The Forster full length dies have a high mounted floating expander. And the neck of the case is held and centered in the neck of the die when the expander enters the case neck. Meaning the Forster expander design reduces neck runout by keeping the expander centered in the case neck.

I get the same neck runout using a Lee collet die or using a separate expander die as I do by using the Forster die with its expander. So why size the case twice when the Forster die does the same thing sizing the case just once.

And in my earlier posting I showed a modified Redding die and adding a high mounted floating Forster expander that greatly reduced neck runout.

And below I replaced all my RCBS die expanders with Forster expanders and spindle assemblies to reduce neck runout. The RCBS expander on the left is raised as high as it will go, and the Forster expander on the right.

And again the 6.5 Guys video I posted has them telling you the Forster die produced less neck runout than a Redding bushing die. And if you have the Forster dies neck honed this could limit you to one brand of brass or even having to neck turn.

 

[carlsbad]

Neither.

 

[Hohn]

I have Forster dies for every rifle I own and none of them have honed necks. And all my rifles are off the shelf factory rifles with SAAMI chambers. I did not have the necks honed so that I can use any brand of brass and in my opinion these dies do not over work the necks.

There is no sense in owning a Forster die if you plan on removing the expander and not using it. The Forster full length dies have a high mounted floating expander. And the neck of the case is held and centered in the neck of the die when the expander enters the case neck. Meaning the Forster expander design reduces neck runout by keeping the expander centered in the case neck.

I get the same neck runout using a Lee collet die or using a separate expander die as I do by using the Forster die with its expander. So why size the case twice when the Forster die does the same thing sizing the case just once.

And in my earlier posting I showed a modified Redding die and adding a high mounted floating Forster expander that greatly reduced neck runout.

And below I replaced all my RCBS die expanders with Forster expanders and spindle assemblies to reduce neck runout. The RCBS expander on the left is raised as high as it will go, and the Forster expander on the right.

And again the 6.5 Guys video I posted has them telling you the Forster die produced less neck runout than a Redding bushing die. And if you have the Forster dies neck honed this could limit you to one brand of brass or even having to neck turn.

Can I assume then you do not have a .223? Because the Forster .223 dies are DEFINITELY very tight in the neck (.240!) and I was having one stuck case after another before I had mine opened up by more than 4 thousandths. I'd suggest that in general the standard Forster sizer is relatively easy on necks, but the .223 is an exception to that.

My loaded 223 rounds at the smallest are 0.248". The forster die is 0.008" smaller than that. On the other hand, my 6.5cm loads are ~0.290 OD loaded, and the Forster die is 0.285 ID. So the larger. The larger die works the necks proportionally a great deal less.

The honed sizes I went with (0.245 for the .223 and .2885" for the 6.5) ended up being just perfect. I can remove the expander and seat a bullet in my brass with 0.002" tension. Also, this seems to entirely eliminate the risk of a stuck case (even with one shot). The high expander is great, but if it's even a tiny bit too high, you will stick cases like crazy. (consider the recommended height setting in the instructions as a "don't go higher" value)

For .223, I have the option to use just the honed Forster (no expander), honed Forster with expander, or honed Forster then mandrel expander.

I haven't tested the difference between them yet, but for convenience, it sure is nice to use the honed forster and skip expanding entirely. You're yielding the neck brass anyway, so why not just yield it with the bullet instead of yielding it twice?

 

[BDman]

I've had my best results with the honed Forster followed by a mandrel. However, I'm about to try it with the factory expander and skip the mandrel step. I found that the factory expander is identical diameter to the mandrel that gives me best accuracy and chrono numbers. I'll also check runout- it's rarely .001 right now. I'll report the results when I get finished.

My die was honed to work with my thickest to thinnest brass and I've had no issues with either. I don't worry too much about over working the necks as I have very consistent NT and have never had a split. I do anneal. Just MHO.

 

[Uncle Ed]

Can I assume then you do not have a .223? Because the Forster .223 dies are DEFINITELY very tight in the neck (.240!) and I was having one stuck case after another before I had mine opened up by more than 4 thousandths. I'd suggest that in general the standard Forster sizer is relatively easy on necks, but the .223 is an exception to that.

I'm loading for three AR15 rifles and two bolt action .223 rifles. And my Forster .223 die does not have a tight neck.

Below are just some of my .223 dies I used and tested over the years, and I prefer using the Forster die with its expander.
So yes I have .223 dies and I did not have my Forster dies neck honed because I want to be able to size different brands of brass. But that doesn't mean if you use one brand of case you can have the neck honed.

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

Forster FL dies, necks honed to .265″, .266″, and .267″.

Are Your Sizing Dies Overworking Your Rifle Brass?
http://www.massreloading.com/dies_overworking_brass.html

Table 2 - Inside Diameter Measurements for 5 different sizing dies

In the chart above the two RCBS .223 dies varied .005 in neck diameter. Meaning chambers and dies vary in size and nothing is written in stone.

 

[Hohn]

Forster specifically lists .240 is the neck ID if their .223 dies. That’s as close to written in stone as you’re going to generally find in this kind of thing.

Also, I’m talking die neck ID, not case Neck ID, which is different.

 

[Webster]

Just to make sure that any imperfections get pushed to the outside even though i did turn my necks. My 308 win brass is about on its 12th reload and i figured I better make sure that the surface where the bullet and the brass mate is straight.

Do you really think tiny imperfections get pushed to the outside?

 

[Uncle Ed]

Forster specifically lists .240 is the neck ID if their .223 dies. That’s as close to written in stone as you’re going to generally find in this kind of thing.

Please post the link to your .240 diameter information, I find it strange that they do not give a plus or minus manufacturing tolerance.

Custom Neck Honing FAQ
https://www.forsterproducts.com/product/full-length-sizing-dies/

Q. How do I determine what diameter to hone my Sizing Die to?

A. Measure the outside diameter of your loaded rounds and subtract 0.004″.

This “hone-to” dimension will prevent the Die from overworking the brass, while enabling the EZ-Out Expander Ball in the Sizer Die to provide consistent neck tension on the bullet.

Two other variables to consider when choosing the “hone-to” dimension are 1) varying neck wall thickness, and 2) differences in ductility, or springback, in different lots or batches of brass.

 

[Hohn]

Hi Ed— if you find the Forster custom neck honing form here, it shows the die neck diameters as shipped as well as the largest ID they will hone (0.008” above standard).

The upshot is that you’d need brass with walls as thin as 0.009” or so to need it.

 

[Uncle Ed]

Hi Ed— if you find the Forster custom neck honing form here, it shows the die neck diameters as shipped as well as the largest ID they will hone (0.008” above standard).

The upshot is that you’d need brass with walls as thin as 0.009” or so to need it.

Normally I prefer to not neck turn my cases, but I have a five gallon bucket full of Remington .223 cases and some have .009 neck thickness variations. I use a Redding neck thickness gauge to sort cases and not neck turn for my bolt action rifles. And the cases with excessive variations are used in my AR15 carbine.

I buy bulk once fired Lake City 5.56 and 7.62 brass for my off the shelf factory rifles with SAAMI chambers. But I also have Winchester, Remington and other brands of brass and I do not need a honed die due to neck thickness variation and brands of brass.

And if you check and see how much your case necks expand when fired in a factory chamber turning the necks will let them expand even more. So what is working your case necks more, the chamber neck diameter or the neck diameter of your die.

The Redding bushing die FAQ tells you if you do not neck turn and your neck thickness varies .002 or more to use their expander.

And my point is there is no point in using a honed die if the neck thickness varies .002 or more. Meaning you need quality brass with a uniform neck thickness or neck turn your cases for good results with a honed die. And the link I posted for the 6mmBR used three honed Forster dies for their no turn neck.