full length or neck sizing on a short fat case?

[CubCouper]

I wouldn't say that "neck sizing doesn't work". In fact, it works just fine... for about 4-6 firings on your brass. Then you'll start to feel a little click when open the bolt. A couple more firings and that click will take a little more pressure to overcome and that's when you start to think about FL sizing or even annealing to "save your brass".

A few years ago I was writing a magazine article discussing the latest annealer. Being a skeptic data analyst. I dove off into the study of cartridge brass metallurgy to test some of the claims that sounded more like hype than science... got a real education in the huge variety of phase changes that brass responds too. Relative to this discussion, when case pressure builds during firing the brass completely expands to the chamber dimension, then shrinks only slightly once the bullet has left, allowing for extraction. If you keep that range of expansion/contraction within about a .001-.002" range cartridge brass alloy can repeat this movement almost indefinitely without any metallurgic change because brass does not work-harden in the same fashion that steel or aluminum does.

Run it through a FL die, keeping the dimensional grow/shrink in the proper range and the cases will reset back to a consistent size all the time. But keep hammering them at the max dimension (neck-size only) and they will harden at that max dimension and lose the shrink factor -- usually leading to difficult case extraction in less than 10 firings. As a side note, when I was testing this, I found that the typical case annealing processes would only bring back the hardened brass for one or two before it was click-y again. Conversely there was no perceived benefit to annealing brass that was always FL resized. The benefit of always FL resizing to that nominal 1.5-2 thou movement is to maintain the full range of growth/shrink ability in the case material.

 

[Mikecr]

CubCouper, the results you describe are no different than it's ever been.
But it often manifests as lack of planning up front, and common shortcut taking.

I currently run a 26wssm Imp that is fitted with absolutely no problems. The ONLY sizing is occasional slight shoulder bumping (due to 35deg shoulders). No body or neck sizing, no annealing, no trimming, perfect extraction. The cases have over 80 reload cycles on them, and are like brand new.

The difference here really is planning and understanding.
It's MY reamer, MY design, My build -just for this.
To begin, 'fitted' is not a 1-2thou range. Truly, that range is appropriate for basic/general function.
My fitting is 1/2thou of NEW cases (fully within spring back everywhere).
My breach is coned & built with enough barrel steel around the chamber for this plan.
The case is improved to remove most angles, and it's alloy and thickness are appropriate for the plan.
The brass was of course measured and plucked from a relatively large lot.

These are basic matters that commonly go without consideration, even while each part of reloading affects another part, and another again.
People change one thing (like clearances) and then whine about it failing for them (the opposite of planning).
That's all that is.
It is true that most common case designs require body sizing, as their design was never centered on reloading.
Their design came from factories selling the ammo. And gun builders want sloppy universal functioning of that ammo.
So anyone trying to eliminate reloading sizing with a standard 30-06/.473 based case hits failure right off the bat.
They need to form & follow a better plan for this.
Like they need to shorten the 30-06 case and form it into 260AI. If they measure good brass & fill out the reamer print & order up an aftermarket action, now they have all kinds of options. It just needs to be fully planned out.
Just an example,, there are options in every cal.

The 223Rem happens to be a cartridge that is suitable for reduced sizing, depending on the chamber, gun build & load.
While there is nothing improved here, it's relative thickness is pretty extreme for case area. With bolt guns I have to bump shoulders with them, and bushing neck size of course, but never any body sizing. So never any FL sizing.

 

[The_Whitetail_kid]

I always do FL on all the cartridges I load for.

 

[SSG Graybush]

I proved conclusively my .223 preferred a neck sized load over full length sized with several five shot groups over several weeks.

I guess when someone whom one respects says something it becomes gospel; facts don't matter.

Your missing the point. No one says that you can't get good accuracy, and maybe even slightly better accuracy temporarily in a rifle with neck sizing. But at some point you must full length size and trim and then you loose that temporary edge. Then the overall accuracy is lost till the brass is formed to the chamber again fully. But I doubt you couldnt get just as good accuracy with the brass consistently bumped 2 thou and annealed every time. People like Brain Litz/Eric Cortina/f class shooters all full length size. If neck sizing was better all the sponsored shooters would do it, but they don't.

 

[Mikecr]

If neck sizing was better all the sponsored shooters would do it, but they don't.

I doubt that. I think most competitors are the very worst for taking shortcuts.
I say that for 3 reasons:

1. Broad claims made by competitors in the past were wrong and/or outright lies.
2. Most competitors merely show up & shoot, prepared or not. Eventually they have a good weekend.
3. If they can't describe technical basis for their claim, that passes all tests (as qualified), then whatever they say is simply baseless and false.

Apply #3, and you won't fall victim to #1
Forget all 3 and focus on cold bore ACCURACY and LR hunting

 

[Rodbolt]

" focus on cold bore ACCURACY and LR hunting"

Words of wisdom.

 

[wdrjr]

I doubt that. I think most competitors are the very worst for taking shortcuts.
I say that for 3 reasons:

1. Broad claims made by competitors in the past were wrong and/or outright lies.
2. Most competitors merely show up & shoot, prepared or not. Eventually they have a good weekend.
3. If they can't describe technical basis for their claim, that passes all tests (as qualified), then whatever they say is simply baseless and false.

Apply #3, and you won't fall victim to #1
Forget all 3 and focus on cold bore ACCURACY and LR hunting

Where I hunt the first shot is the only shot.

 

[Far North Hunter]

I full length with either Redding or Wilson bushing dies. Only bumping enough to chamber with a slight feel of pressure (except hunting loads). Am I wrong in assuming by using neck bushings, which only step down the neck roughly 60%, I am leaving the neck that is not resized at roughly chamber dimensions? I believe I'm getting a hybrid effect of neck sizing, partial FL sizing and a minimum shoulder bump. Feeling I am maximizing cartridge/chamber axial alignment.

 

[Mikecr]

I don't think alignment matters. FL sized cases are typically way out of chambered alignment, and they still shoot well.
A good throat is barely1/2thou over cal, and neck release allows the bullet free to adjust axially(within that 1/2thou) during engraving.
What can matter is chambered runout of the loaded cartridge. This causes chamber pressure points.
If you were to press a thumb against the chamber in the middle of a string, you could see what that does.

While your loaded runout is lower than your clearances, you should be clear of chamber pressure points.
Most people find that relatively high runout makes no difference to results - because it's relative to high clearances.
Shove bananas into a tight chamber and you'll likely throw shots everywhere. Some competitors have done this, and their only relief seams bigger sizing and more clearances. The problem is, this is their cause of runout to begin with, and excess of anything added isn't free.

Many don't get that their chamber is their best die. Everything is setup to plan right there.
And the tighter your best die (your chamber) to new brass, the lower the yielding of that brass. It's less energy added, and less spring back variances. Your brass comes out of that smoking chamber as straight as it will ever be.
Then, if you don't resize the living nonsense out of it, you can again reduce energies added to your brass, keeping it straight.
Straight ammo does not bind in any fashion when chambered. It lies in your chamber consistently and stress free.

There is little 'good' about sizing brass. Right?
It reforms what your chamber establishes. It work hardens brass. It rolls brass, thick toward thin, up the case to land on your bench with trimming. The upsizing with a sloppy chamber isn't free either. That's a lot of yielding, and brass always wants to go where it's been.
You can never restore a brass character so far departed from. I submit that brass character must change some with every cycle of firing upsizing followed by FL downsizing.
Sizing (up/down) causes you to have to replace brass.

Ideally, no sizing die would ever touch your brass, and your plan would allow the brass to stabilize to perfect function without sizing dies.
Ideally/unlikely, but as you near this, you'll find that your actions potentially allow brass to last a lifetime.
Whether a competitor or not, consider all the benefits in that.
Stable capacity
Consistent response to pressure
No trimming
No annealing
No loosening pockets
No replacement/re-fireforming
No lot changes or shortages

It may not be for everyone (it isn't), but it's not all doom & gloom either.
I don't blame folks for going with minimal sizing, and I also don't feel sorry for them when they did so without a plan.

 

[RichCoyle]

I wouldn't say that "neck sizing doesn't work". In fact, it works just fine... for about 4-6 firings on your brass. Then you'll start to feel a little click when open the bolt. A couple more firings and that click will take a little more pressure to overcome and that's when you start to think about FL sizing or even annealing to "save your brass".

Run it through a FL die, keeping the dimensional grow/shrink in the proper range and the cases will reset back to a consistent size all the time.

You are looking at things the way you want them to be, not the way they are. The .223 I referred to in the earlier post would fire seven full throttle loads. At which time I full length sized it, NOT to "save your brass", but to get it to easily fit back in the chamber for neck sizing to extract the mast accuracy it could produce.

I now have two custom chambers and full length both every time. But if I adjust the die the way we are instructed in the die box the shoulders bump back too little or too much. Therefore, I have to back the die out and size each one INDIVIDUALLY to get the .001" bump I want.

 

[cdherman]

I think this whole thread is an exercise in terminology.
There are several methods of resizing.

-- neck only. Dies for this truly do not touch the shoulder or body. You really achieve what MikeCR describes -- a cartridge formed to YOUR gun. Positive, it can result in more accuracy. Negative --you may have extraction and for that matter chambering issues over time. Brass can spring back less and less. And because brass experiences work hardening, the extent of the above can vary. So as much as a perfect sized to your gun case is a GOOD thing, variable neck tension is a BAD thing. And I am not sure that annealing and neck sizing are very much compatible......

-- FL resizing with minimal shoulder bump. I think that is what many of you are referring to as "FL resizing". But its not. Its adjusting the FL die to bump the shoulder .002" or so. It usually means a bit of body resizing and it usually means you can chamber the resized round well in your gun (read - useful for rapid fire or hunting). Personally, I think this is where to go for long term brass life and decent accuracy, as well as good working loads.

-- FULL FL resizing. This is when you adjust the die to the old school book instructions and dial down the die till the press fully drives the case and the shell holder ALL the way in. This is what can result in case head separation over time in a generously head spaced gun. Moreover, sized this way, any gun with much "loose" tolerances, will have the cartridge sort of "laying in the chamber". Small for the space. Poor accuracy IMHO. BUT -- if you anneal and resize all you cases this way, you achieve consistency. Some times consistency trumps all the other theoretical crap. So the guys that truly FL resize every time might have it right. JUST -- case life is a bona fide negative to this approach.

I am not sure any approach is prefect. You would never go on a bear hunt with neck sized brass. And if you are shooting paper or woodchucks who cares if you have a problem finally.

IMO, true FL resizing is needed for autoloaders and dangerous game. Some of you that throw away brass like butt wipes can FL resize everything but at $1 plus a hull, I like to keep mine around......

 

[RichCoyle]

Mikecr,

One time I made a Short Fat Seven using .378 Weatherby brass. I didn't size it at all. I formed it with just enough clearance so the fired case could still hold a bullet. It worked exactly as planned.

 

[RichCoyle]

Your missing the point. No one says that you can't get good accuracy, and maybe even slightly better accuracy temporarily in a rifle with neck sizing. But at some point you must full length size and trim and then you loose that temporary edge. Then the overall accuracy is lost till the brass is formed to the chamber again fully. But I doubt you couldnt get just as good accuracy with the brass consistently bumped 2 thou and annealed every time. People like Brain Litz/Eric Cortina/f class shooters all full length size. If neck sizing was better all the sponsored shooters would do it, but they don't.

There is no point to miss. I never had to trim the brass and never lost accuracy neck sizing. Every time I full length sized I lost accuracy on that load. For the next seven loads the accuracy was as good as when I first discovered what the rifle liked. Back in those days I didn't know anything about "bumping the shoulder back .002".

I just remembered I only sized the neck about half way and nothing else was sized until after the seven neck sized shots were fired.

 

[Mikecr]

There is a body die, bump die, body-bushing die (including shoulder in bushing, or not), custom bump-bushing dies, neck sizing die (collet or bushing), mandrel expansion dies, FL sizing die (which has no bushing or collet).
We can adjust each to plan, and any can be custom to fired brass.