FL sizing in two steps vs. one step

[JMayo]

Do you imagine that we've reached the end of all learning here?
That we should concede to declarations with no more basis than call to authority fallacies?

Meaning there is so much totally useless babble that the op"s topic is washed out ... Ps where did you copy that last sentence be from? Jk lol

 

[Coyotefurharvester]

If the chamber is concentric to the bore and the bullet is seated into the lands with minimal headspace why would any run out matter? Even seated 0.050 off the lands the bullet will enter the lands before leaving the case neck, I don't have any run out measuring equipment(not going down that path).

 

[darkangel_r2]

The systems that controls the most contact surfaces at the same time usually results in the most repeatable result. Resizing systems that touch different surfaces at different times will induce inconsistencies.

Neck sizing usually works well in tight neck chambers using low neck tensions. If you only have to move the brass OD .004"ish total to hold a bullet the fact that the shoulder and body are unsupported during this operation matters less. Strong brass, flash hole pilots, and annealing to keep the neck soft and the rest of the case harder can also help here. Also high polished die and testing different lubricants to minimize case neck friction is a good thing here.

But expander balls and expander mandrels also size without support. If you can get them to be just barely larger than the sized ID of the brass so they really just smooth out the inside they won't hurt much. I think downward sizing operations have more support than upward due to case geometry having more support going down than up. So if you have to move a good amount of metal increasing the neck ID I think mandrels do it better than expander balls.

Standard full length non bushing dies with a high polish interior usually produce the highest degree of dimensional consistency and concentricity because all exterior surfaces are supported at the same time if you thread the die down far enough to move the shoulder. Get it custom neck honed to the desired neck tension and add an expander ball that just barely touches the ID on the way out and you can have extremely consistent and reliable results with only one operation. Or if you keep your chamber neck clean and you neck turn after the first resizing with the expander in you can probably skip the expander on subsequent resizing.

A custom neck honed die and a couple of expander mandrels can give you plenty of neck tension variation to play with and barely move the brass if you are okay doing 2 operations.

 

[darkangel_r2]

You also have to bring in the subject of annealing in any of
the test results. Some mention spring back, but that should
not be the case with a proper anneal. When running a mandrel
after annealing, I'll get a few cases that push harder then normal,
and I'll set them aside for foulers.

Good policy, same here.

 

[darkangel_r2]

If the chamber is concentric to the bore and the bullet is seated into the lands with minimal headspace why would any run out matter? Even seated 0.050 off the lands the bullet will enter the lands before leaving the case neck, I don't have any run out measuring equipment(not going down that path).

The more canted the bullet is when impacting the lands the more unbalanced the jacket damage will be and the more time it will take for the bearing surface to be aligned and formed to the rifling. Jam loads do a lot to smooth out inconsistencies in both of these issues.

Longer bearing surfaces reduce bullet cant as well.

 

[spike-55]

On my fls dies like the Forster’s, I will drop case back down spin it 180 and do it again like 2 step seating. I’m sure it doesn’t do a damn thing but work my brass more, but it makes me feel good!

lol - me too!!! i also mark the same spot on each case and load that spot the same in the chamber in each round- again I’m sure it doesn’t do a damn thing for accuracy, but it makes me feel good!
stan

 

[D-4297]

As Ned Ludd , and others have said . Trying different ways to do this is really the only way to get where you are attempting to go . No two rifles are alike , or shoot alike . Nor are any two chambers , or rifling . Even when cut with the same reamer . Personally ; I use a Redding Type "S" F/L , Bushing Die , followed by a Carbide expander , for my TR rifle . My Open rifle gets fed brass from a Whidden custom F/L Bushing Die , also followed by a custom Carbide Expander . I checked for T.I.R. when I first began searching for the "BEST" way , and found that ammo that as .001 was more than adequate , and the process I follow achieves this . And as someone else mentioned , Annealing is also a major factor ; if it is involved in the process . The real conclusion is that there is no singular "RIGHT , or "WRONG" way to get there . Only what you have found works for you , and your rifle . The Target will tell you when you get it "RIGHT".

 

[spike-55]

No need for a mandrel if using the appropriate bushing that gives the best result on paper.
Isn't your bullet a mandrel so to speak?
I personally use Redding and Wilson FL bushing dies and seat with a Redding competition seater.
Just sold my concentricity gauge too.

and wilson makes some FL bushing small base dies that will also work. works the brass bit more, but it's the primer pockets that go first most of the time??j not sure what all calibers that are available.
stan

 

[PracticalTactical]

There is a widespread opinion that the best way to FL size your brass is to (a) resize the neck with a bushing neck sizing die (usually Redding) and then (b) resize the body of the case with a body die (people recommend also Redding for this operation). The rationale behind this process is that it should produce more concentric rounds in comparison to running a standard FL die (without expander ball+expanding the neck with a mandrel in a separate step).

The 2-step process is obviously less time efficient, so is it worth extra effort?
I didn't find answer in this thread

Two step sizing question...

So I was reading an article over on the Rifleman's Journal, where an experiment was performed that examined order of sizing operations versus concentricity readings. The findings showed that sizing a case by taking the neck down in two steps first sizing with a bushing neck die then sizing...

forum.accurateshooter.com

Getting really nice concentric rounds is real easy.

First, stop thinking that a variety of convoluted sizing practices are going to change the mechanical reality of metal forming.

Second, you will never find runout on a fired case... The runout is created by the sizing process and by how much sizing you are doing.

Accept that the more you size the brass, the more runout you will invariably induce. By contrast, the less sizing you do to the brass the less opportunity there is to induce runout. You cannot create 0.004" runout by reducing the neck only 0.003" Its not possible unless your die is severely damaged.

Third, make sure your ejection from the rifle is not damaging the case necks and setting you up to fail. If your case mouths are D shaped, then you have to address that.

Fourth, if you run a tight neck chamber and relatively low neck clearances, you will not need to size very far and will by default have low runout.

Lastly, in a properly chambered rifle, your free bore diameter will align the bullet with the rifling. If the free bore diameter is too loose, then a tight neck clearance is your last line of defense to start the bullet into the rifling straight.

If you have a sloppy free bore and you do not neck turn, the ogive will start into the rifling straight enough if you jam the lands but the tail end is going to rattle around and find its way into the rifling at odd angles and you will not get great accuracy and short of a fresh chambering job, you likely wont.

 

[Kracken McGraw]

lol - me too!!! i also mark the same spot on each case and load that spot the same in the chamber in each round- again I’m sure it doesn’t do a damn thing for accuracy, but it makes me feel good!
stan

I bet we are controlling spring back a little bit more putting the brass necks up in the die twice like that. If a guy owns several presses, he might as well get the goody out of them!

 

[tom]

Any number of processes can be used successfully. Heck I've broken agg records trying out 3 different ways to get to the end goal. And people I trust are successful doing things in steps I've not even tried. My current method is one step, but I was able to replicate the agging capabilities of a good rifle with use of a mandrel a few years back. I don't mandrel currently, but have been beat by people who do. I don't anneal, but have been beat by people who do. I don't clean brass.....you get the picture. Just try some shit until you're satisfied is my advice lol.

Tom

 

[Bc'z]

Any number of processes can be used successfully. Heck I've broken agg records trying out 3 different ways to get to the end goal. And people I trust are successful doing things in steps I've not even tried. My current method is one step, but I was able to replicate the agging capabilities of a good rifle with use of a mandrel a few years back. I don't mandrel currently, but have been beat by people who do. I don't anneal, but have been beat by people who do. I don't clean brass.....you get the picture. Just try some shit until you're satisfied is my advice lol.

Tom

I'd say that about sums it up. Lol

 

[Old Tanker]

Do you run a mandrel after that or not?

No, because I’m only in to the game of shooting smaller groups today, than I did yesterday. If I were shooting BR competition, maybe.

 

[Beiruty]

Take a FS side, remove the decapping pin. Bump the shoulder of the case 0.003". Use a mandrel to expand the neck 0.002" under the bullet diameter.

 

[Fuj]

Just try some shit until you're satisfied is my advice lol.

Tom

And that's the bottom line.

 

[BoydAllen]

Boyd
I’m sensing frustration in your text ? Maybe I’m wrong.
Jim

Not frustrated, just wanted to know. This thread started with a statement that is totally inaccurate, so I wanted to know what kind of equipment and what experience. Essentially, I am puzzled as to how the conclusion was reached. A more logical approach might have been to ask what people's experiences has been with two step resizing. I have done it combining a collet die for necks with a body die, for cases that are not turned, with excellent results. I have passed this on to others who have done and reported the same thing. If you want to have the straightest cases, order a custom fL die that has a neck ID corresponding to the smallest bushing you would use, and use an expander die and mandrels to open it up slightly if you want to experiment. To illustrate, pull the exapnder out of an off the shelf one piece FL die and size a case that has only been turned enough to clean up the neck. I think that your concentricity gauge reading will make you smile.

 

[mikecr]

A more logical approach might have been to ask what people's experiences has been with two step resizing.

This is true for sure. Otherwise it's setup for mob -vs- gang battle, instead of logical discussion.

Along the line of PracticalTactical's input, I see the chamber as my best die.
I couldn't be happier with my cases as pulled from a smoking chamber, and it's sad in a sense that anything I do to it from there represents detriment. So what I do is minimal.
I do not do anything that leads to repeated brass trimming, constant annealing, opening pockets, or replacements. Every die I have/had are custom in some way or otherwise just right for my sizing plan.

I could do it with a custom FL die, but I do not want to size FL of necks. I want separate adjustment of neck sizing lengths and I like that I can change bushings. I mandrel expand separately for similar reason.
All necks turned.
For case bodies, I don't want cases growing and going to popping extractions and loosening pockets, so I never 'let' them do that. If a case does anyway, it will forever want to go back there, so I toss it.
This is for small hunting cartridges, 223rem, 6br, 6dasher, 6XC, 260AI, 26wssm, etc., at or near SAAMI max.
So I keep chambers tight at webs, letting my chamber/breech support be the die. The lowest sizing I do is 1-1.5thou shoulder bumping with body dies set up as bump dies.
Something would be bigly broken if my loaded runout exceeded 1thou. That's just no way.

This works as good as it gets for me. An example of how someone could separate sizing & why.
I know it wouldn't work for a 30-06, nor be competitive with a 6PPC. But I don't shoot those.
If I did, then I might have gone rat turd in a violin case, and reformed my brass with every reload cycle.
And I'd be trimming and annealing and/or replacing brass constantly I'm sure.

 

[drop_point]

Loading for PRS, I often had to deal with cases that had been on the ground and were just nasty. Often the cases were stepped on, and almost all the round would have "D-shaped" case mouths. I would also have to process a lot of cases very quickly. I opted for a progressive press for doing this. I used a process that was contrary to conventional wisdom, and similar to OP's scenario.

First, I would tumble the brass to remove debris.

I would run the brass through the press twice. First time through, I would use a universal decapping die in position one, a mandrel in position two to get the necks round again, a body die in position three, then an S-type neck die in position four. Then I would tumble again so that cases weren't sticky from lube.

On the second time through the press, I would run through the universal decapping die to ensure the flash hole was clear, prime on the downstroke, through a mandrel again, then to a funnel die, and then seat.

This resulted in two pulls of the handle per piece of brass. I would usually get 0.004" of TIR or LESS, often LESS. I had tried the same process with a regular FL die with an expander ball initially and results were all over the place. Was it the press? Was it the die? I don't know, but I changed things one process at a time until I got desired results. That is where I ended up. I think its important to recognize that processes may have different results for different people. There is no universal way of doing things, only trends. As always, there are multiple ways to skin a cat. Its the results that matter most.

 

[JFrank]

@Dave M. if I had a proof, I wouldn't be posting this thread. I know several F-class or LR shooters who follow this path. I used to do the 2-step process, but I got back to an FL die+carbide mandrel after that for time saving purposes.

What is a carbide mandrel ?

 

[marchx]

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