current thinking: expander ball vs expander mandrel

[flexible]

Hi everyone, flexible here. Starting to set up my T7 turret with dies for a new rifle.
Previously I took the decapping pin and expander ball out of the sizing die and used an expander mandrel.
Is that still the best of current thinking?
thanks

 

[quest450]

expander ball could introduce runout, if you're looking for accuracy I'd clean up or turn necks and use a bushing to size necks after testing neck tension on paper

 

[LCazador]

Like the post above says expander ball can produce runout. Why use an expander at all? Use a bushing die and size neck to desired neck tension.

 

[Walt Krafft]

I use a mandrel to push any irregularities out away from the bullet. My seating pressure got much more uniform when I did this.

 

[jepp2]

Is that still the best of current thinking?

Depends. How much work is your expander ball having to do? Or another way to ask this, is how much under-size does your reduce the neck under the desired dimension?

Even when lubing the inside of the case neck, using a carbide expander, and setting the expander high so it passes through the case neck just as it leaves the neck portion of the sizing die, I found if the expander has to increase the neck by 0.002" or more it WILL pull the case neck and increase TIR.

 

[K22]

I use expander balls in my F/L standard RCBS dies but I am not advocating that this is in anyway superior to mandrels especially if you are seeking ultimate accuracy such as in the benchrest or F Class shooting disciplines. I use them because I want to keep the reloading process as efficient (short but effective) as possible with the least of amount of equipment.

If you want to use them, I can share some tips that I found aid in obtaining sufficiently accurate reloads for my purposes which is about 1/2 to 5/8" moa for varmint and predator hunting. Here are some things I do which I believe make using expander balls more effective.

1. I brush out the necks with a stiff nylon brush using a low RMP drill to remove excess carbon on the inside of the necks.

2. I polish the expander ball with very fine grit emery cloth to produce a mirror like finish which reduces drag of the neck. This only needs to be done once.

3. I de-prime cases with a de-priming die. I set my expander assembly higher in the die (but not in the neck sizing area) which I found minimizes neck distortion and also reduces felt drag.

4. I have a set of expander ball assemblies, sized in .001" increment that I can interchange depending the rifle / brand of cases that reduces drag on the neck. This is a similar concept to the set of different Whidden Gun Works sizing buttons. This is the K22 adaptation.

I found that consistent neck tension rather than some absolute number is more important in maintaining consistency in my reloads. I stopped measuring run out many years ago since I never could associate it with results of target perhaps because I am not shooting benchrest level accuracy.

 

[Bc'z]

expander ball could introduce runout, if you're looking for accuracy I'd clean up or turn necks and use a bushing to size necks after testing neck tension on paper

Are you in the camp that the bullet is the mandrel?
I am.
I'm in total agreement with bushing die and proper interference.
I was turning my Peterson brass for neck clearance in chamber, it had to be done.
Zack sent me 2 boxes of Lapua with specific instructions.
"Don't fuk with it!" I followed his instructions and my clearance issue solved.

 

[Murray Brook]

Try the Lee Collet die. Inexpensive and gives you very low case neck run-out. JMO

 

[quest450]

Bc'z.....Yes but neck prep must be perfect in order to get uniform and consistent neck tension and bullet release, I let the carbon build up inside my necks for lubrication and sort my seated rounds on AMP press so I shoot my sighters and score rounds with almost identical neck tension

 

[Bill K]

They all do a job in sizing the brass in reloading. It narrows down to what you think works best and floats your boat. It is a personal choice on what and how you do your load makeup.

 

[quest450]

They all do a job in sizing the brass in reloading. It narrows down to what you think works best and floats your boat. It is a personal choice on what and how you do your load makeup.

not really, what I or anyone else thinks is irrelevant, you test and let the paper tell you what your barrel likes......paper doesn't lie

 

[flexible]

Depends. How much work is your expander ball having to do? Or another way to ask this, is how much under-size does your reduce the neck under the desired dimension?

Even when lubing the inside of the case neck, using a carbide expander, and setting the expander high so it passes through the case neck just as it leaves the neck portion of the sizing die, I found if the expander has to increase the neck by 0.002" or more it WILL pull the case neck and increase TIR.

thanks everyone, I'll stick with my current setup. I wonder why the die manufacturers put the expander into their sizing dies

 

[Bc'z]

thanks everyone, I'll stick with my current setup. I wonder why the die manufacturers put the expander into their sizing dies

They put he expander button in so as to decap, size your brass in 1 motion for your average reloaded, this worked great for me 26 years ago when I began rolling my own, but as I evolved as a shooter looking for the smallest groups and Precision from my rifles, my gear evolved with me.

 

[Coyotefurharvester]

Most of my loading is a gutted FL sizing die, than a -0.002 mandrel just before loading. Currently I'm messing with finding a good "generic" 223 AR load with the Hornady 2266 bullet(55 gr btsp) a decent cheap bullet. Using FC range brass, H335, ARM primer, 2.220 coal (all brass sized same) 3 different rifles have been pretty consistent sub 1 inch 5 shot groups at 100 yards. Using the die/mandrel method. I do run them thru a Lee fcd (light) for AR use. Going to try the same load thru a couple bolt guns when the range dries up.

 

[Capt. Oblivious]

Nothing goes down my necks except a bullet, I just run a proper bushing in my DIEs with turned necks

 

[Mark611]

You guys can use all bushing dies you want! get rid of the expander ball and use a LEE Collet die! simple and easy, you can get the proper size Mandrel from LEE for your needs if you don't like the 1 that came with it, I turn my necks to my needs first with new brass and the size only with a body die and then the LCD, I get very precise cases less than 1k runout and the neck tension I want, my accuracy tells all the story I need to see YMMV

 

[dusterdave173]

I was talking to Mr Whidden last week and ask this very question--he said
Button or mandrel if they were the same size that he could not see a difference on a 1000 yd target

 

[Bill K]

Agree, but, that is exactly what is part of working up a load. Especially for a given firearm, rifle or handgun.

not really, what I or anyone else thinks is irrelevant, you test and let the paper tell you what your barrel likes......paper doesn't lie

 

[misser]

i would be lost with a mandrel setup in a press

 

[JSH]

I know little. But I try to read a lot and make a decision by what others have found.
Mandrel or bushing, I think the key is the neck turning. An even wall thickness.
Unturned brass, if there is runout, either one will still leave runout, could be inside or outside.
The 6BRs I have or had all seemed pretty good. Yet a skim turn to knock off the high spots usually showed some improvement.
My 22BR was supposed to be a no turn as was my 20BR. The 22 I did a skim turn on just to clean it up, but without over working the brass.
The 20BR had to have a heavy cut for clearance but has been a pure joy to work with.
Turning or skimming for a factory chambered gun may or may not do you any favors, from my findings.

I have mandrels but have went with a proper bushing for clearance and found no difference in using both.

Decap rods with expander ball, I makes sure and use lube inside.