Expander ball vs M die

[bandw1dth]

What would minimize runout more? The expander ball on the full length size die or a mandril like the M die? I'm toying with the idea of taking the expander ball out of the size die and expand the neck with the m die. What's your take on this? Would this also keep the cases from growing since the expander ball isn't being drug through the neck anymore?

 

Thanks guys

[Chills1994]

It's kinda spendy, but I hear the Redding bushing dies work well.

 

I also hear the bushings to get are the TiN coated ones.

 

I bought some pre-processed Lake City brass that once I loaded up wasn't grouping worth  a darn at 100 yards.

 

I bought some machinist type idicators and magnetic bases and made my own concentricity gauge at first.  My reloads had like 8 thousandths in runout.

 

And just to confirm it, I blew about $420 on a commercially made concentricty gauge.  I got the same exact numbers as far as runout goes.

 

Then I bought some XM855 and XM193 ammo.  That stuff grouped like crap too.  Then I put some of that stuff through my concentricity gauge.  Sure enough, over 5 thou in runout.

 

So now the remaining 990 pieces of pre-processed brass...I am running those through a full length resizing die with  the decapping rod (and expander ball) removed.  

 

And for the few dummy rounds I have made so far, I have just been using boat tail bullets without expanding the neck.

 

It seems to work fine now and my fancy schmancy concentricity gauge says bullet runout is just one thou.

 

I have a Lee FCD as the last station in my Dillon 650.

 

The dummy rounds have been case gauging just fine too.

 

You could always try using a universal decapping die, and then your full length resizing die with its decapping rod removed.  If you already have a universal decapping die and a full length resizing die, that might be the cheapest option of them all versus buying the Lyman M die or the Redding bushing die with maybe 1, 2, or 3 TiN coated bushings  (to get the neck tension just right).

Edited May 5, 2017 by Chills1994

[bandw1dth]

It's kinda spendy, but I hear the Redding bushing dies work well.
 
I also hear the bushings to get are the TiN coated ones.
 
I bought some pre-processed Lake City brass that once I loaded up wasn't grouping worth  a darn at 100 yards.
 
I bought some machinist type idicators and magnetic bases and made my own concentricity gauge at first.  My reloads had like 8 thousandths in runout.
 
And just to confirm it, I blew about $420 on a commercially made concentricty gauge.  I got the same exact numbers as far as runout goes.
 
Then I bought some XM855 and XM193 ammo.  That stuff grouped like crap too.  Then I put some of that stuff through my concentricity gauge.  Sure enough, over 5 thou in runout.
 
So now the remaining 990 pieces of pre-processed brass...I am running those through a full length resizing die with  the decapping rod (and expander ball) removed.  
 
And for the few dummy rounds I have made so far, I have just been using boat tail bullets without expanding the neck.
 
It seems to work fine now and my fancy schmancy concentricity gauge says bullet runout is just one thou.
 
I have a Lee FCD as the last station in my Dillon 650.
 
The dummy rounds have been case gauging just fine too.
 
You could always try using a universal decapping die, and then your full length resizing die with its decapping rod removed.  If you already have a universal decapping die and a full length resizing die, that might be the cheapest option of them all versus buying the Lyman M die or the Redding bushing die with maybe 1, 2, or 3 TiN coated bushings  (to get the neck tension just right).

So did your groups end up shrinking after you got runout down to 1 thousandth?

I wet tumble my brass so that means decapping with my universal decap die first. Typically I've been taking the decapping pin outta the fl size die since there's no need for it anymore and leaving the expander ball in there. I've no idea what the runout ends up at with letting the expander ball do its thing. I do got a buddy that just got a hornady concentricity gauge so I think I'm gonna help him put it to good use.

Since I got my mr bullet feeder I had to get the m die to open the neck up just a hair to stop the bullets from tipping when the shell plate indexes. And then use the Lee fcd to snug the neck up after seating, no "crimp" per se just removing the flair.

I'm thinking I'm gonna take the whole decap / expander ball rod outta the size die completely and let the M Die expand the neck. So on my LnL I'll have it as follows;

Station 1 - Lyman M Die

Station 2 - powder

Station 3 - bullet drop

Station 4 - seating

Station 5 - Lee FCD

[Kaldor]

Good info here and Id like to see a response from Chills too as I dont own a run out gauge.

 

Im pondering doing the same thing.  When I do my prep runs I run Lee decapper in 1, Hornady sizing die in 3.  I have also polished my expander ball to about .220" in an attempt to combat brass spring back that inevitably happens over time on cases with 5+ firings on them.  Trimming is done on WFT2 post sizing.  

 

When loading I run M-Die, Drop, Seater, FCD.  Seems to be working decently as Im pushing groups in the .400-.500" range on a consistent basis.

 

Im not sure if the smaller expander ball is helping, but I do worry about the M-Die by itself not being able to create as straight of a sizing which should reduce run out at the end as I get when I neck size at .220", then finish that last couple thou with the M-Die when I load.

[bigedp51]

The biggest cause of neck runout is from the expander being locked down off center. With Forster benchrest full length dies with high mounted floating expander you will get very low runout. This is because the neck of the case is held and centered in the neck of the die when the floating expander enters the neck.

 

A second method is to remove the expander and use a expander die like the Lyman type "M" die or Sinclair expander die. These type expander dies can not pull the neck off center. It is my understanding that the Lyman type "M" dies are more commonly used on progressive presses. The two step type "M" die will expand the case mouth and help reduce runout during seating. The second step allows you to start the bullet into the case neck with just your fingers and thus starts the bullet straight into the neck.

 

 

Below the Forster benchrest sizing die and benchrest seating die that greatly reduce runout.

 

 

The seater die chamber holds the case and bullet in perfect alignment and can even reduce runout slightly.

Below I replaced all my RCBS expander assemblies with Forster units to reduce neck runout.

The RCBS expander on the left is raised as high as it will go next to the replacement Forster floating expander.

 

 

The Lyman type Expander die will work with any type die and aids seating with standard dies and reducing runout.

Edited May 6, 2017 by bigedp51

[Chills1994]

Well...gents...

 

The few dummy rounds I made were done one at a time on my 650.

 

So out of this first batch of pre-processed brass I had, there were just 36 I had left that I ran through my RCBS X die with the the decapping rod assembly removed.

 

All those came out with really low runout at the case mouth.   I want to say like just 1 thou.

 

So about an hour ago, I dumped into my 650's casefeeder, and then swapped out the toolheaded....added more H335 to the powder measure, then added primers.

 

Then I checked the powder charge.

 

Then I started cranking.

 

After about the 15th round, I started noticing little copper shavings.

 

Yep, it looks like the case necks/mouths got squeezed down too far.

 

:-(

 

So for the next batch, I'll try running them through the RCBS X die with its mandrel screwed in.  It doesn't have your typical decapping rod with your usual expander ball.

 

I am going to order the M die and Redding bushing dies.

 

I'll try shooting the others with the nicked jackets...oh...in about 8 hours.  The runout on these, at the bullet, jumped up to about 3 to 4 thou.  

 

Arrghh...

 

 

So I am not expecting success as far as grouping goes.

[Chills1994]

My just recently reloaded rounds show about 0.246 or 0.247 outside diamer at the case neck with the bullet seated.  

 

As the brass comes to me pre-processed, they also measure about 0.247 at the case neck.

 

I didn't even think of measuring the cases that I had ran up into the RCBS X die.

 

So when I start up again, I'll have to measure brass as it comes out of the X die body.

 

And then insert the X die mandrel, and measure the case necks after that.

[Chills1994]

I jad some black hills factory ammo, and they also measured 0.247 (with the bullet still seated in the case) for an O.D. of the case neck.

 

 

[Chills1994]

I am at the range now and this is the 5 shot group I just shot at 100 yards:

 

 

The penny is in there just for scale.

 

The AR was shot off a bench with a tripod type rest under the FFT and a leather bunny ear bag under the buttstock.

 

These were the rounds where I resized them in my RCBS X die with the decapping rod removed.  And the same rounds where, I'm guessing, the mouths were pinched down too far and shaved off little pieces of copper from the bullet jackets.

 

As a side note, I just make my own targets out of 8.5X11 printer paper, and 3 inch by 3 inch post it notes.

 

I trace around a Home Depot paint stirring stick to get those four lines.

 

The lines end up being about 1.125 inches apart.

 

Back on topic....so now I am debating on that Lyman M die and/or the Redding bushing die.

 

In away it would be to reassuring NOT to see copper flakes on my 650's shellplate.

 

 

 

 

[Kaldor]

Looks like a solid group.  Id run it

[dauntedfuture]

I have tried all kinds of dies.  Unless you are turning necks you really need an expander ball with bushing dies to provide the most consistent neck tension without turning necks which is a no-go for three gun. Otherwise your id will vary with brass thickness.  there is really not a downside to using an expander ball with Redding dies.  An m die will work about as well.    the advantage the Bushing dies will provide is that you're not working the brass as much but you still need to end up with an id that's .221-.222 for a semi auto or about .002-.003 neck tension.  

[Matt in TN]

On 5/15/2017 at 6:12 PM, dauntedfuture said:

I have tried all kinds of dies.  Unless you are turning necks you really need an expander ball with bushing dies to provide the most consistent neck tension without turning necks which is a no-go for three gun. Otherwise your id will vary with brass thickness.  there is really not a downside to using an expander ball with Redding dies.  An m die will work about as well.    the advantage the Bushing dies will provide is that you're not working the brass as much but you still need to end up with an id that's .221-.222 for a semi auto or about .002-.003 neck tension.  

 

This.  The only downside to leaving the expander ball is that it can increase small variations in headpace and runout.  But as the man says - in 3-gun it doesn't matter, and brass life and neck tension matters more.

 

The M-die sure is nice for loading flat-base bullets though.  I'd call it a "must have" if you're going to do very many of them.

Edited May 17, 2017 by Matt in TN

[Chills1994]

I would be curious if a regular full length resizing die with the traditional expander ball makes the cases grow more than whatever "body" die plus an M die.

 

If you actually got your brass back, and went with the body die + M die, it would be cool if you didn't have to trim every time.  

 

I only have a little bit of experience with the RCBS X sizer die, but you have to trim your brass to 1.74" first (or 20 thou under the max length).  I have so much brass now it would be a total PITA to keep the shorter X-die'd brass separated from all the rest.  Plus, I have to wonder at what point....after how many firings...does splitting case necks become an issue.

 

I think for most 3 gunners here running their brass through an annealer would be over the top...much like turning necks would be.

 

[dauntedfuture]

There are a thousand ways to load ammo and they are all "Right"  I would suggest that the proof is in the pudding; you should evaluate a sample of ammo before you run a large batch.  I have loaded quality ammo with all kinds of dies and set ups and brass is usually the largest contributing factor for runout, I have some 7.62 LC91 that sucks no matter what I do.  Total indicated runout or variations in case measurements (not headspace, that's inside the rifle) can be indicators that you have problems that could be a bent decapping rod or not getting enough lube inside the case necks.  I try to load 10 rounds and check the runout on each one as well as put them into a case mic, if everything is still set up right, runout will be low and shoulders will be in the same place 

[bigedp51]

Using a expander is not the end of the world as many people claim.

 

1. First polish the expander, below is a "unpolished" RCBS expander from a .223 die. A unpolished expander will cause "more" drag and pull the necks.

 

 

2. Lube the inside of your case necks. (And "stop" being a uncaring Ewok)

 

 

Edited May 24, 2017 by bigedp51

[bandw1dth]

Just got the results back from my buddy that has a concentricity gauge and my loaded rounds have about 7 thousands runout. Which explains why they won't group for shit.

I've decided to order the Redding body die and lee collet neck sizing die. I think I'm gonna run a little test and load some up using the body die + m die to expand the neck and then load another batch up using the body die and lee neck size die and hopefully after that test I'll have a set up that will give me under .003 runout which is what I'm shooting for.


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[Chills1994]

Welllll...that's the first step in the scientific process, right?

 

Identifying the problem.

 

Here is a video of my homemade concentricity gauge:

 

 

 

Which is a steel block with 4 pieces of slingshot ammo and a backer plate welded to it.  And then there is a magnetic base with a "total indicated runout" gauge (aka lever gauge) attached to it.

 

Not as elegant as the $120 plus commercially available concentricity gauges, but worked good enough.  And buying used machinist's tools off of Craig's List  came out cheaply enough.

[Chills1994]

As a side note....I have read on other forums that one should NOT lock the decapping rod assembly down super tight on your full length resizing die.

 

Basically, leave it loose with some float, so as your (polished?) expander ball pulls back through the neck, the tension is applied downward and the decapping rod assembly is pulled in line with the case.... instead of a tight decapping rod assembly pulling the neck/mouth off center.

 

Well, that's what I read anyway....

[bandw1dth]

As a side note....I have read on other forums that one should NOT lock the decapping rod assembly down super tight on your full length resizing die.
 
Basically, leave it loose with some float, so as your (polished?) expander ball pulls back through the neck, the tension is applied downward and the decapping rod assembly is pulled in line with the case.... instead of a tight decapping rod assembly pulling the neck/mouth off center.
 
Well, that's what I read anyway....

Leaving the decapping rod loose only makes sense when you think about it. Thanks for the tip.


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[bigedp51]

Or you can buy a Forster full length benchrest die with the high mounted floating expander. The neck of the case is held and centered in the neck of the die when the floating expander enters the case neck. And the expander can not pull the case neck off center, out of all the dies I have the Forster dies produce the most concentric case necks.

 

 

Below my modified Redding full length .243 die with a Forster expander assembly installed that greatly reduces neck runout vs the oblong Redding expander.

 

NOTE, the lock ring has a rubber o-ring under it that can be tightened but still allows the expander to float and self center in the case neck.

 

 

Below I installed Forster the high mounted spindle and expander assemblies on all my RCBS dies to reduce neck runout.

On the left is the standard RCBS expander raised as high as it will go and on the right is the Forster unit.

 

 

If you just make the standard expander slightly loose and not held and centered by the die, the expander can still pull the case neck off center.

Edited June 2, 2017 by bigedp51

[Kaldor]

On 5/24/2017 at 3:45 PM, bigedp51 said:

Using a expander is not the end of the world as many people claim.

 

1. First polish the expander, below is a "unpolished" RCBS expander from a .223 die. A unpolished expander will cause "more" drag and pull the necks.

 

 

 

2. Lube the inside of your case necks. (And "stop" being a uncaring Ewok)

 

 

 

 

The Hornady expander is much smoother than that, and even more so after I sanded mine with 2000 grit wet/dry sandpaper.  Right now it measures at about .219" post sanding, and in combination with the M-Die I think Ive found a winner.  I dont specifically lube inside my case necks, but I will get a little of the lanolin/iso lube in the case neck when I lube cases.  So every 4th or 5th case, its good enough.

 

[bandw1dth]

 
The Hornady expander is much smoother than that, and even more so after I sanded mine with 2000 grit wet/dry sandpaper.  Right now it measures at about .219" post sanding, and in combination with the M-Die I think Ive found a winner.  I dont specifically lube inside my case necks, but I will get a little of the lanolin/iso lube in the case neck when I lube cases.  So every 4th or 5th case, its good enough.
 

So your using the hornady expander ball as well as the M die? Why not just size with the hornady die and expand with the m die?


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[Kaldor]

23 hours ago, bandw1dth said:

 

So your using the hornady expander ball as well as the M die? Why not just size with the hornady die and expand with the m die?


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Because I dont feel the M-die is gradual enough.  I dunno, thats my reason and Im sticking to it.  

 

I process a few thousand pieces at a time and at the bottom of my bin of ready to load 223, I have some brass that might have be sitting for a couple years.  My sizing runs are Lee decapper in 1, sizing die in 3.  I run my M-die in station 1 when loading and do the final neck sizing right before I seat the bullet.  I was also getting some spring back post sizing as my brass ages, and by using a undersized expander I am eliminating that.  Also, wet tumbling can and will slightly peen case mouths, so the M-die brings them back into round nicely.