Resizing with full length or neck sizing die?

[kherter]

What is the best way to resize your cases for accuracy? Is it best to just resize the neck and leave the case formed to you chamber or does it really matter? If you could give me some of your expertise on what you do and how you go about it that would be great, thanks.
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[woods]

OK there are lots of ways to skin a cat but I'll take out my knife first.

I like to use a Lee Collet Neck Sizer and a Redding Body Die combination. The Lee Collet will size the neck with no lube, no expander ball jerking on the neck and with very little runout. The Redding Body Die will size the case body and push the shoulder back if needed.

IMO it is important to size the case body for 2 reasons:

1. Mainly the brass in the case body can be banana shaped and if you don't size it so that it does not bear on the chamber, then it will push your case so that it may not orient the neck and bullet in line with the bore. Also if the centerline of the case neck is not aligned with the centerline of the case body then you may not be orienting your bullet in line with the bore.

2. Also chambers are not perfect and unless you can chamber the fire formed case body in the exact same orientation everytime then you may get a different orientation of the neck and bullet in line with the bore.

I also set the shoulder position for very slight contact between the case shoulder and chamber shoulder, called a slight crush fit.

To help orient the neck and bullet in line with the bore, I also leave part of the fire formed neck unsized

I do this by putting a washer around the case on top of the shell holder with the Lee Collet

If you are using a bushing die (which I have for a couple of calibers) then you can adjust the die to size only part of the neck. Then use the Redding Body Die.

So the case body is not in a bind in the chamber and the fire formed portion of the neck and the sloped shoulder contact orients the bullet in line with the bore.

Just my way, next cat up for skinning

 

[Mikecr]

It's Chevy/Ford on this....
I partial NS with a Wilson bushing, and bump shoulders/min body size with JLC or Redding body dies. Much of it for just the opposite of what is commonly thought.

1. Sizing rarely reduces runout, but increases it, including firing in a chamber(your best die) -beyond initial fireforming.
2. No reason to size more of the neck than gripping the bullet bearing(oversizing).
3. No reason to oversize -anywhere.

There are qualifiers to different approaches, like pressure, brass quality, chamber fit, etc. In the end, you either control these or do the best you can with the results.

 

[BountyHunter]

Go to 6mmbr.com and read this article on adjusting and using FL dies

Bedeviled by Bump — When Full-Length Dies Don't Work « Daily Bulletin

Second, I just got Tony Boyers new book on accuracy shooting and he really confirms that FL sizing is the way to go for extreme accuracy.

Plus it absolutely has the the best and clearest explanation of die adjusting, shoulder bumping and why it works and does not work and the reasons for it. Tony Boyer is the top BR shooter around and people have been waiting for several years for his book and I see why now.

IMO there is a clear reason most of the top LR,,SR BR and Palma shooters FL resize.

Key thought is a properly fitted die.

BH

 

[boomtube]

"What is the best way to resize your cases for accuracy?"

If there was a " best" way to do anything we would all do it that way. We don't.

I know what works best for each of my rifles but I have no idea what will work best for yours, experiment.

 

[MSLRHunter]

I prefer to full length size mine. I use the Hornady headspace guage to properly adust my full length sizing die to very minimally size the case. I am getting excellent case life due to the minimal sizing and very consistent

 

[flashhole]

Second, I just got Tony Boyers new book on accuracy shooting and he really confirms that FL sizing is the way to go for extreme accuracy.
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Key thought is a properly fitted die.

BH

It's tough to apply broad sweeping generalities on this because you will find differences in chamber dimensions between bench rest guns and hunting guns. I agree with everything BH said but with the caveat you have a "match" chamber to start with. You just have to figure out what works best for your gun. Both my small caliber rifles have very tight chambers and FL sizing works best for them. My 25-06 on the other hand gets best accuracy when necksizing only because it has a more generous chamber (thanks for that Ruger) and my 7mm RM is in the FL sizing category as well.

 

[BountyHunter]

The issue is not a "match" chamber, and having one or not having one is not the issue. Your chamber must be uniform most of all then the issue is sizing with dies that match whatever chamber you have.

If they do not, you will not get the best accuracy no matter what you do and the NS cases will continue to change dimensions and work harden, eventually have to be resized and annealed or thrown away. If you allow them to grow and harden without sizing it is not conducive to best accuracy. Now if strictly factory chamber, factory barrel and factory dies run all with way to the shellholder, then do whatever you want as it is not going to matter much anyway.

Match chambers are normally minumum SAAMI specs to minimize case expansion and sizing due to differences in brass and chamber. Now most are cut in the throat for a specific range of bullets versus a longer throated factory reamer.

You can send your factory dies to Jim Carstenson at JLC Precision and have them honed to match, or he can make a custom FL size die with bushings from a redding body die for $80

If you ever use a proper fitted and adusted FL die you will never NS again.

The problem is most have not and see NS as the cure all for ill fitting dies and improper die adjustment.

BH

 

[flashhole]

It's interesting to note how many people who handload don't measure how much they set the shoulder back on the case. They just go through the exercise. Measuring is the only way to tell what is going on.

 

[Mikecr]

Let's be logical here...
Referenced notions of a successful competitor could very well provide neither basis nor validation -without logical understanding and a mountain of qualifiers.
Is FL sizing really better -for quicker BR shooting between conditions, or better for point blank BR grouping, or for OUR hunting accuracy?
Is there any logic behind FL sizing as better across the gamut of HUNTING cartridges?

Three things anyone here can validate & apply to the question:
1. Sizing will not reduce H20 capacity variance over fireformed cases.
2. Sizing will not reduce TIR over fireformed cases.
3. FL Neck sizing will not reduce tension variance over partial neck sizing.

Check em yourself.
And there is basis I'm sure for each contributing to accuracy.

Now when I think of a custom die, I consider one that provides absolute minimal change from the best a case can be (fully fireformed, straight, consistent in capacity, neck tension, and correctly headspaced). And in my exerience this is way less common than off the shelf FL dies provide.
Consider the weekly problems questioned here arising from FL sizing & compare this to rare problems from the ranks of partial sizers. The reason partial/seperate sizers have less problems, is because they're dealing with each factor seperately. This is apparently more manageable than trying to do it all in one action.
Check this as well.

If custom-minimal sizing works, and I don't hear alot of grumbling that custom dies don't, then why couldn't seperate addressing of the 3 factors above suffice? I'm saying it can and does. Both work.
So I suggest it's Chevy/Ford, because there are shooters doing well with both approaches.
It's merely an abstract of a collective lacking any LAWS to follow.
Friggin chaos!

 

[BountyHunter]

Let's be logical here...
Referenced notions of a successful competitor could very well provide neither basis nor validation -without logical understanding and a mountain of qualifiers.
Is FL sizing really better -for quicker BR shooting between conditions, or better for point blank BR grouping, or for OUR hunting accuracy?
Is there any logic behind FL sizing as better across the gamut of HUNTING cartridges?

Three things anyone here can validate & apply to the question:
1. Sizing will not reduce H20 capacity variance over fireformed cases.
2. Sizing will not reduce TIR over fireformed cases.
3. FL Neck sizing will not reduce tension variance over partial neck sizing.

Check em yourself.
And there is basis I'm sure for each contributing to accuracy.

Now when I think of a custom die, I consider one that provides absolute minimal change from the best a case can be (fully fireformed, straight, consistent in capacity, neck tension, and correctly headspaced). And in my exerience this is way less common than off the shelf FL dies provide.
Consider the weekly problems questioned here arising from FL sizing & compare this to rare problems from the ranks of partial sizers. The reason partial/seperate sizers have less problems, is because they're dealing with each factor seperately. This is apparently more manageable than trying to do it all in one action.
Check this as well.

If custom-minimal sizing works, and I don't hear alot of grumbling that custom dies don't, then why couldn't seperate addressing of the 3 factors above suffice? I'm saying it can and does. Both work.
So I suggest it's Chevy/Ford, because there are shooters doing well with both approaches.
It's merely an abstract of a collective lacking any LAWS to follow.
Friggin chaos!

Mike

This is as logical as it gets to the question of which is best for "accuracy".

No one said anything abut FL size H2O variance, but that has zero to do with sizing so got to say that is in left field
No one said FL size will reduce TIR, but then neither will NS. So what is the point. However a properly sized die will undisputably.

As to the tension variance, that certainly is debatable when you consider a "NS only" case indisputably will continue to grow and work harden at a larger size each time due to less spring back and WHEN resized finally will not normally come down as uniformly as a case minimally sized each time.

Can anyone explain the concept in detail how a case body is allowed to grow each shot and work harden often at different rates and how that is an accuracy enhancing attribute over a case that is minimally sized each time to a uniform dimension? I have been waited for this explanation for a long time. To me, that belief has to defy all concepts of logic.

Now you mention sizing in three steps with separate dies as working. I would agree because it is not NS, rather it is FL sizing using 3 different dies, hopefully matching so what is the point. Anyway you cut it, that is still FL sizing, not NS unless we have suddenly redefined NS only sizing.

98% of the weekly problems you attribute to FL sizing are simply due to improperly adjusted and ill fitting dies which is another problem all together and has absolutely zero relevance to the FL or NS question factually.

The big arguement for NS only seems to be is that it is the answer technique that does not do it all the way right, but is harder to mess up? OK, I will buy that one as long as we are only talking about "hunting accuracy" and "doing well " whatever that is.

However, most guys here at not talking simple "hunting accuracy (.5-.75 MOA) and doing well"; they are after maximum accuracy. Max accuracy is the same for short range BR, LR BR, Palma, NRA LR or hunting. The steps and process are the same normally, the parameters of accuracy are defined slightly differently but in the end, most of the top shooters in any of those have learned that to get the best accuracy, you FL size. You control the brass dimensions totally. Now it can be one step or three, but it is still sizing the whole full length of the case not just the neck.

We know for a fact that a 338 Lapua case can be FL sized 54 times in a proper fitting die and shoot a world record of five shots in 1.4" at 1000 (Tom Sarver and his 300 Hulk). That set of cases was finally canned at 84 reloads. Has anyone seen a NS only case do that?

BH

 

[Mikecr]

In contrast
My 6.5wssm has over 30 reloads without ever FL sizing or trimming or annealing. Each case is exactly where they were set by the second fireforming. Same length, same web dia, same neck tension(and I measure it -everytime), very low TIR, and matching in H20 capacity.
They are not lengthening, or work hardening, because I DO NOT FL size. I DO NOT size the entire necks. I DO NOT size the bodies(which causes lengthening).
I don't have to.

I partial NS, mandrel expand necks, and bump shoulders.
That's it. It's more than I would have to do. And it's not FL sizing.
My qualifiers:
I cull out thickness variance before initial preps,, turn necks for proper chamber fit,, my bump dies are custom,, chambers are tight,, and I keep my loads at or below SAAMI max(or the point where fireformed brass yields beyond springback, as seen by .0005 further growth .200 from heads).

For many cartridges and reloading needs, you have it backwards BH.
-It's FL sizing that rolls brass from low in the body all the way to the case mouths, causing stress, lengthening, and donuts. I don't have dounts, my brass has not been moved one bit.
-It's FL sizing the entire necks(often beyond bullet bearing), causing greater tension variance, removing a valuable tuning adjustment, and increasing runout. I measure and set matching tension on each reload with a loadcell, by varying sizing length and/or cycling expansion.
-It's FL sizing that brings the devil out of brass(stress induced springback variance), causing increasing runout with every single cycle. My runout increases very little, because I don't move brass, and each rational firing cycles it only within springback.
-It's FL sizing that causes H20 capacity to climb over reloading cycles, as it's trimmed it away.
Did I mention that I don't have to trim?

Does Tony account for these? Does he match H20 capacities, or qualify ogive radius, bearing & meplats, or even weigh powder? Does he shoot something other than a 6PPC, or 30BR, at extreme pressures and close ranges? Has he ever needed to hit his mark -without sighters? Anyway...
My extreme has qualifiers, and I'm aware of FL sizing qualifiers and needs.
FL sizing is required for cases exposed to high pressures, and/or poorly designed with high body taper, high length to width, and low shoulder angles.
Barring these factors, it's my contention that FL sizing is never needed and detrimental to LR accuracy.
I think it's possible Tom could have done even better. But not with any of my guns, and off a bipod in the field. Was his 1.4" ACCURACY(0.134moa), or PRECISION? What does he do consistently?

This isn't blasphemy, but a necessary review of context.
I don't compete, but learned from David Tubb not to rely on competitive abstracts or anomalies for basis. I think this can be reasoned through to a truth, which will stand as passing all tests.
We can't just declare that so&so did this and was successful, or so&so didn't with the same results.
This is not a path to any real understanding.

 

[BountyHunter]

Mike

Last I knew there are only two commercial bump dies. One only bumps and one sizes and bumps, so which commercial die are you recommending everyone use as 98% of these guys are using commercial dies only?

So you have custom bump dies made that do not touch the body? Interstesting, but expensive when same thing is available commercially now, IF it only bumps the shoulder.

Plus I saw nothing stating that you have to control the bump to .0001 to .0015 or less in order to keep from pushing out the body shoulder junction and getting a failure to chamber while using a true shoulder bump only die that does not touch the body anywhere. Anything over that and you will get a hard to chamber in a shoulder bump only and it is possible even in FL die if you push too far back like the instructions often say on how to adjust. I have found that it really requires a custom bump guage as the Hornady set is hard to get accurate measurements most of the time.

Many guys are not capable of making that measurement accurately so how do you recommend they control setback at that body junction if using only a bump die?

As for the attributes of partial NS, once again any standard FL bushing die does the same except for the Neil Jones which have a full length neck and bump bushing built into one.

Expanding mandrels are a well known trick to maintain uniformity in the necks and a lot of LR shooters have been doing that for years. We have also been using pin guages +- .0005 to measure exact variance and seaters with pressue readings while seating bullets. As far as I and everyone else has seen, that is the only way to truely measure neck tension during the seating, anything else is just a WAG. Even that is not agreed as 100% accurate by some.

Your method sounds like you are trying to control tension in the NS with a load cell by changing the NS depths? Now if NS only elimates work hardening in the neck as compared to FL sizing as you claimed, why is that even necessary?

Why attempt to control neck tension if NS only eliminates the problem as you claim?

when you look at what you say works, in reality I fail to see how it is practical for 98% of the loads shot here. You say you have to keep them below SAAMI max in order to stop springback. As to you not get springback each and every time a round is fired, I disagree that you are not getting springback unless you have found a way to redefine the law of physics. Even 40,000 PSI will cause a brass case to expand and springback. That is undisputable in any ballistic lab or reference book for anyone to see. Plus a 6.5 WSM has a max SAAMI of 65K PSI so pretty **** sure, you are getting springback and work hardening inthe body and neck too whether you know it or not.

Must be why you have to control NS depth to control non existant variance in neck tension.

Plus most loads here at at SAAMI max at least I would bet if you put a strain guage on them. We have smiths telling them load until bolt stiffens up or locks and then back up 2 grains.

It is amazing that every and I mean every SR and LR BR shooter who NS only claims they get 4-6 or so reloads only before the "click" of where the case has expanded to hard to open and close and must be set back by FL sizing. Now they are using custom chambers and custom NS dies. that is a well known phenomanon so what are they doing wrong?

So best I can see you are the only shooter known that does not get springback and loads shoot forever without increasing in the body and shoulder. Maybe that is due to well below SAAMI max?

You and I certainly agree that standard FL dies improperly adjusted with normal expanders cause many problems.

I routinely use exanders and a custom honed body die and then NS IF I have a problem with a cartridge/load combo and neck tension. So I totally agree that can be one of the best ways to control variance in neck tension, except I size the body with custom honed body die.

However, all the unfavorable attributes you claim are due to FL sizing, we all know that is simply due to improper adjusted dies and expanders, not correct FL sizing. Proper sized dies and adjusted do not cause case growth and I shoot a lot of wildcats and magnums and have for years (300 WSM, 30 Hart, 300 RUM, 300 Weatherby, 300 Ack Imp, 338, 338 Ack Imp, 338-408 are just some). I can load to max SAAMI (if it even has a SAAMI in most cases and have single digit ES and SD in most cases with max accuracy and long case life.

I have 300 WSM cases loaded to shoot 210s at 2960 FPS (yep, pretty sure that is right at SAAMI max), single digit ES and SD for competition and have over 35 reloadings on them too and still ticking, so I know what I say works for accuracy and case life. I have tried the NS only route and it will bit you IMO.

as for your question is FL sizing better for hunting accuracy? IMO 110 % yes over NS only. IF you FL size with proper adjusted dies you will never get a failure to chamber at the wrong time because the case grew as we routinely seen with NS only in big magnums especially.

Anyway, interesting take and I see now that you are going way over NS only with stock commercial dies which is a key factor.

BH

 

[Mikecr]

Last I knew there are only two commercial bump dies. One only bumps and one sizes and bumps, so which commercial die are you recommending everyone use as 98% of these guys are using commercial dies only?

I use Redding body dies honed by JLC

So you have custom bump dies made that do not touch the body? Interstesting, but expensive when same thing is available commercially now, IF it only bumps the shoulder?

I never said my dies don't touch the bodies. They squish & confine the bodies within springback, leaving zero body sizing, while containing the bump action.

Many guys are not capable of making that measurement accurately so how do you recommend they control setback at that body junction if using only a bump die?

I use a couple gizzys I've bought(Tubbs), or had made with barrel finishing. If not for that, I'd make something myself. It is only a relative measurement(like bullet seating measurements) and nothing difficult about it, as confirmed by chambering feel on each one. It typically takes 4-5 firings before my brass has settled into 0-HS. From there, I'm forced to bump a thou everytime.

As for the attributes of partial NS, once again any standard FL bushing die does the same except for the Neil Jones which have a full length neck and bump bushing built into one

Great. I just happen to prefer Wilson NS and seating dies.

sounds like you are trying to control tension in the NS with a load cell by changing the NS depths? Now if NS only elimates work hardening in the neck as compared to FL sizing as you claimed, why is that even necessary?
Why attempt to control neck tension if NS only eliminates the problem as you claim?

I don't think I said anything about work hardening a neck. My implication of FL tension variance relates to uncontrolled tension beyond bullet bearing, affecting desired tension on the bearing. Tension from neck sizing grows as it nears the shoulder junction. I suggest 'uncontrolled', because there is no way to adjust it out seperately(so why put it there). As far as work hardening, it is managed through tight fit and minimal neck sizing. Nothing new, no claims of mystical discovery..
My loadcell is built into my Sinclair expander die and I measure using their hardened turning mandrel. My adjustment amounts to seperate thickness spacers used with my Wilson NS die. Sometimes I go back & forth between em a couple times to get a baseline match. When it gets to be any kind of pain, I'll stress relieve the necks with a lead dip.

You say you have to keep them below SAAMI max in order to stop springback. As to you not get springback each and every time a round is fired, I disagree that you are not getting springback unless you have found a way to redefine the law of physics. Even 40,000 PSI will cause a brass case to expand and springback. That is undisputable in any ballistic lab or reference book for anyone to see. Plus a 6.5 WSM has a max SAAMI of 65K PSI so pretty **** sure, you are getting springback and work hardening inthe body and neck too whether you know it or not.

Must be why you have to control NS depth to control non existant variance in neck tension.

Plus most loads here at at SAAMI max at least I would bet if you put a strain guage on them. We have smiths telling them load until bolt stiffens up or locks and then back up 2 grains.?

- I never said anything about stopping springback. Springback is our friend. I stay below YIELD(exceeding springback), and with cartridges like a 6br or 6xc, this can be measured at ~56kpsi(per QL predictions). Most cartridges SAMMI max at 55kpsi, some up at 65kpsi. But there is absolutely no reason for me to go that high and I don't. When I load develop, I measure web growth and see it settle into springback range of the chamber. As I continue upward, I'll see .0005 growth from that point and stop. That is 'Mikecr Max'. I run it with QL and log it for future load what-ifs.
What people do based on what people do, is their problem.
- And I don't shoot a 6.5wsm...

It is amazing that every and I mean every SR and LR BR shooter who NS only claims they get 4-6 or so reloads only before the "click" of where the case has expanded to hard to open and close and must be set back by FL sizing. Now they are using custom chambers and custom NS dies. that is a well known phenomanon so what are they doing wrong?

Well, have they considered the costs of extreme pressure loads? There is a price for everything.
I don't think I would be surprised, it's pretty simple really.

So best I can see you are the only shooter known that does not get springback and loads shoot forever without increasing in the body and shoulder. Maybe that is due to well below SAAMI max?

It can't be done with every cartridge & load. I can do it with body taper <15thou/inch, shoulder angles +30degs, neck clearance <2thou and within Mikecr Max pressures. This is common territory for varmint cartidges.
Now my 223 cases will not last so long without trimming(looks like ~13 reloads), and perhaps I need to explore different sizing, maybe even FL, or live with the life provided by my methods, or drop the cartridge. It's a poor design.
So you got me there. And I'll concede that to be point blank competitive, high pressures are needed, and that FL sizing with this right from the git-go makes sense.
But that doesn't mean FL sizing always makes sense.

If we're bantering extremes at both ends of a scale, it's because there is rarely a single 'right' approach that applies across the board. Many are right between us.
Great thread & discussion!