Mandrel vs Expander button in a die

[Ccrider]

If you are trying to increase or decrease neck tension by changing the bushing size, to do this want you have to also change the mandrel or expander size?

 

[searcher]

I think the ideal situation is to use a floating expander ball that has been taken down in size by application of sandpaper or (preferably), a diamond file while in a lathe or drill press until it slides out of the sized case with almost no friction. I do this step after selecting a lot of brass (whether neck turned or not) A tight expander ball or locked-in or off-center mandrel will only mess your accuracy up. It is very easy to get the die interior perfectly round - not so easy to get a button or mandrel perfectly centered - no matter how good the die or who it is made by. That is easily confirmed by checking neck runout after sizing brass without the ball/mandrel - then measuring again after using them. As for less force needed to seat a bullet after having used a mandrel - that is because there is more "dwell" time at the point of where the brass is being opened up - or stretched than when using an expander ball which has such a small contact area with the brass. Nevertheless - that lighter feel of seating the bullet doesn't translate the same way when the bullet is being pulled out. A neck with a thicker wall is still going to have more resistance on exit.

 

[INTJ]

If you are trying to increase or decrease neck tension by changing the bushing size, to do this want you have to also change the mandrel or expander size?

The way I do it is use the expander to set neck tension and then pick a bushing that works with that.

 

[bozo699]

The way I do it is use the expander to set neck tension and then pick a bushing that works with that.

Never quite looked at it this way but it makes perfect sense.
Wayne

 

[Ccrider]

If your Es is single digits, what is the chances of neck tension being inconsistent?

 

[Richard Coody]

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

Threads on this forum always seem to get a little out of hand. This is one. All these methods can load perfectly satisfactory ammo. I see no reason for shooters to be applying benchrest reloading tecniques to average rifles. They are just setting themselves up for disappointment. Unless you are measuring progress by tenths or less you are wasting time and money.

I use whidden's full length die with his expander ball kit. Loads great ammo. Very concentric. No reason it shouldn't work just fine with his bushing die and expander ball kit.

I also use Harrell bushing dies and the k&m expander mandrel kit. The thing about a bushing is it pushes all the inconsistencies to the inside. The mandrel sets the final neck tension and pushes the inconsistencies to the outside where they have less effect. If you are going to this extreme you should have already moved to neck turning.

For most shooters they will get perfectly acceptable results using a forster benchrest sizing die with expander ball. I know for many of my rifles its all I need.

 

[Matt in Virginia]

FWIW,
Another option you may consider. I've had good luck with Redding FL S type bushing dies, Redding Ti Nitride Bushings, capped with a floating Redding Carbide Expander Ball. Die tuning and decent brass can produce superb results. IME...

Regards, Matt.

 

[Richard Coody]

FWIW,
Another option you may consider. I've had good luck with Redding FL S type bushing dies, Redding Ti Nitride Bushings, capped with a floating Redding Carbide Expander Ball. Die tuning and decent brass can produce superb results. IME...

Regards, Matt.

I just set up another redding bushing die a few minutes ago to neck down 6.5 grendel to 6mm. Die is hitting the shell holder with only half the neck sized. Going to machine about 60 thousandths off of the die Monday.

Just going to use this die for necking down brass. As soon as i have some fireformed brass I will send it to whidden and have a set of custom dies made.

 

[TackDriv3r]

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.

Reviving an old post, would the Forster expanders work with both the Redding full length non bushing and bushing dies?

 

[Bill Norris]

Reviving an old post, would the Forster expanders work with both the Redding full length non bushing and bushing dies?

I think they would work if you are using them without installing them inside the Redding die and separately. But not if you are referring to installing them in the Redding die.

 

[TackDriv3r]

I think they would work if you are using them without installing them inside the Redding die and separately. But not if you are referring to installing them in the Redding die.

I was curious to install the Forster stem and button inside the Redding die, since I removed the Redding buttons because it tends to pull the necks out of alignment, been using Sinclair carbide mandrels . 001" and .002" under bullet diameter with a seperate Sinclair expanding die as a 2nd step. I liked the idea where the Forster button sits further up on the stem than sitting way lower on the stem like the Redding.