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Neck sizing vs full sizing question.


Condition1

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Knocked up 50 6.5crdm and some 308.

did some organising as my reloading room has got a bit out of hand, found the cases for my dies to put them away for a change and noticed both lee cases had neck sizing decapping dies.

is there any down side to using these instead of full length sizing every time? Do I still need to use lube?

thanks 

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Even Lyman -who has been selling reloading equipment since the 1800's- no longer says there is any benefit to neck sizing with regard to accuracy nor case life. I only neck size for a few cartridges, under very circumstances. I FL resize everything else. ~Andrew

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2 hours ago, Andrew said:

Even Lyman -who has been selling reloading equipment since the 1800's- no longer says there is any benefit to neck sizing with regard to accuracy nor case life. I only neck size for a few cartridges, under very circumstances. I FL resize everything else. ~Andrew

There's full length back to SAAMI / CIP and there's tweaking the shoulder back to a set amount right for one chamber,  there's no good reason to F/L to SAAMI if restricting reloads to particular rifles (bolt action, not semi-autos).  IMHO of course.  Shouty American video not withstanding.

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As per PbG,

’just enough’ FL resizing is IMHO the way to go. ie size to suit your chamber in your rifle. No need to smash back the brass to SAAMI/CIP minimum specs. 

I body size as a separate operation, just pushing the shoulder back a few thou.

Cannot see any advantage or reason to size any more than this or to ‘not’ do this.

T

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+1 on terryh's & Popsbengo's replies......also notwithstanding shouty American video...😂😂

I reload for a number of calibres, mainly old military rifles & F/L resize back 2-3 thou from my fire-formed cases about every 4-5 reloads & neck size in between. The cases are fire-formed to your rifle after all.....I found this to be the average time the bolt just about starts to get slightly heavier to lock down (depending on powder, load, calibre & brass quality) & then the shoulder needs to be bumped back slightly. As terryh also says there is no need to push the brass way back to SAAMI/CIP specs every reload, in my case I found that to be so, particularly in .303 British as it can lead to case head separation, especially with poor quality brass. ..... All this of course depends on whether or not you are reloading for one rifle, if 2 or more different rifles in the same calibre you will of course need to keep the cases separate to each rifle or F/L all cases every time to a spec that one size fits all.....

Unless you have titanium bushing neck dies or the Lee collet neck die you will need to lube imo.....👍

DeLaRue

 

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Time to throw another log on the fire ...

In my few weeks of handoading, I have never seen a case that was “overworked by F/L sizing.” I have seen case head separation, I have seen neck splits, I have seen failing shoulders, and most of all, I have seen primer pockets that are so enlarged the primers don’t stay in. I have yet to see a case fail because of F/L sizing overwork.


Case head separation is caused by someone not knowing how to set their sizing die ,But if you set your sizing die properly, it will never happen and I don’t even bother checking that.
Split necks are caused by the use of standard sizing dies (N/S or F/L) where the mouth of the case is closed more than it should be and then expanded again by the expander ball. This occurs more often from rifles with a generous leade where the case mouth expands more than usual. When you work that case mouth with a standard die over and over again, it will split. You can alleviate that with annealing but even more specifically by eschewing the use of standard dies and using a bushing die with the proper size bushing and placing the expander ball in low Earth orbit where it belongs.
Failing shoulders is very rare and I have seen that with certain specific ancient calibers and with people using body dies. (Hold that thought, we’ll come back to it.) When you resize the case or more commonly when you use the body die, the shoulders do not go back properly and they crumple. This is very rare, but I have seen it.
The most common cause of death for a rifle case is the loose primer pocket. This will occur when you foolishly insist on using very stout loads in your rifle. That’s what kills my brass, because I do use very stout loads. I believe I **** the primer pocket expansion by using a small base F/L die from the first sizing as it pushes the case head back together some after each firing. I get 8 loadings with my brass from virgin and then I retire it. By that time the primer is VERY easy to insert.

Overworking my brass due to sizing? I don’t even know what that would look like. Do you?

Now that we have shot that first canard down, let’s go after the second one; brace yourself, it’s going to be rough.

When you neck size, the only thing you are doing is pushing back the neck to a smaller dimension, the body and shoulder of the case are untouched.
Now, when you fire a cartridge for the first time in your action, the principle of operation is for the case to expand until it is stopped by the chamber and it can’t expand any further. The mouth of the case expands also to obturate the bore and prevent the hot gases from going back into the chamber and your face. Everything goes out the barrel. When the pressure drops, the case shrinks back, a little, and comes off the wall. The bolt rotates the case to break any remaining stickiness and then pulls the fired case out of the chamber.
Brass has some elasticity inherent to it. This is why the case does shrink back a bit so you can pull it out. However that elasticity can be overcome with too much pressure. This is what happens when a bolt is hard to open. The brass was overworked due to too high a pressure and will not shrink back. When you try to rotate the bolt, the case is stuck to the wall of the chamber and it will not let go easily.

Ok. Now when you neck size, you do not bring back the case to a starting volume. The case now has the volume of a fired case that has shrunk back a bit. The next time you fire it the case expands again and shrinks back, but less than the prior time. Your twice-fired case now has an internal volume that is even greater than after the first firing. At some point, the N/S case becomes too difficult to rotate and extract. Neck sizers pull out something called a body die (told you we would come back to it) or may even decide to F/L size the many-times fired case to bring it back to “normal.” That doesn’t really work, the body die will bring it back some, but the brass will also spring back larger because that’s what brass does. So, even after using a body die, you have no clue about the internal volume. If you have to use a body die or if you have to F/L size the case at intervals, you do not have a consistent internal volume, especially between the load prior to the use of the body die and the load right after the use of the body die. You have no consistency from load to load.
Another reason you use the body die is to set the shoulder back some. This means that in the interval between the first firing and the time you use the body die, the shoulder has expanded, firing after firing. Another area of inconsistency, but it gets worse. This is actually how you damage your rifle.
Your bolt action should not be used to crush fit a fat cartridge with a too long neck either. If you do that consistently you are damaging your action; the lugs, the handle, etc. They are designed to hold the cartridge in place during ignition, to obturate the bore, not to coax bad cartridges into the chamber.
But it gets worse. If you have ANY resistance when you open the bolt and pull out the fired cartridge, you’ve got an overpressure situation. That can be caused by a bad load or by an ill-fitting cartridge, either way you are doing damage to your action. I know that a lot of neck sizers decide it’s time to use the body die when the bolt gets really hard to close or open; they are causing damage to their rifles, on top of getting inconsistencies from load to load.
A properly adjusted F/L resizing die for a single rifle should put the shoulder back about .001 to .002 from fired, squeeze the body and shrink the neck and mouth. When you load a handloaded cartridge, the bolt should close smoothly without any resistance whatsoever. When the shot is taken, you should be able to open the bolt without a hint of resistance then either. If there is any resistance anywhere, you have a problem, if it persists, you are damaging your rifle. If you open your bolt and hear a click at the top of the stroke, you’re really damaging your rifle.

Because of the tightness of my chamber, I could probably get away with neck sizing the case since it does not have much room for the brass to grow unlike factory rifles with their obese chambers. I F/L size my fired cartridges after every firing because I insist on the highest consistency between loadings and I absolutely must have the smoothest possible action travel.the very last thing I want is to be fighting with the action at every shot. I place the cartridge in the action and I close the bolt just before I fire. It’s ALWAYS as smooth as butter; no resistance. 

Happy new year ! 

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23 hours ago, Popsbengo said:

There's full length back to SAAMI / CIP and there's tweaking the shoulder back to a set amount right for one chamber,  there's no good reason to F/L to SAAMI if restricting reloads to particular rifles (bolt action, not semi-autos).  IMHO of course.  Shouty American video not withstanding.

I would agree to an extent. There are some rifles that I FL resize for a clean fit in the chamber, but not with the die screwed all the way down.  For some rifles, however, I size them to spec. I have, for example, five 6.5 Creedmoor bolt actions and one autoloader. Sizing down to factory spec (Small Base FL die) and loading with my H4350 target loads -which shoot exceptionally well in all of these rifles.- simplifies my loading immensely. My hunting loads will get a different bullet of the same weight loaded to the same OAL. I do much the same for 308 and 30-06. 223 / 5.56 is another.

I know. Some are you are thinking, "What a bottom feeder this guy is!"  I can see that, but I load very good ammunition so it works for me.~Andrew

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To F/L or Neck size is a debate that has raged on for years with entirely valid reasons offered up for both.....personally I think this is a case of whatever works for you &  your rifle.

Shooting F class compared to .303 rifles that are between 115 & 65 years old are about as far apart as it gets & personally having tried both I will stick with my reloading methods for my rifles whilst respecting all & any opinions that might differ from mine. Whether you have been loading for many weeks or decades you learn something new all the time, it's what makes reloading such a fascinating part of our hobby. The main thing is we are all shooters enjoying our sport & long may that continue.....

May I wish you all a safe , healthy & Happy New Year!

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9 hours ago, Andrew said:

I know. Some are you are thinking, "What a bottom feeder this guy is!"  I can see that, but I load very good ammunition so it works for me.~Andrew

Not at all!  Your experience and contribution is most welcome. 

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22 hours ago, One on top of two said:


Case head separation is caused by someone not knowing how to set their sizing die ,But if you set your sizing die properly, it will never happen and I don’t even bother checking that.

For the benefit of us smaller brained kreechers, could you tell us how the dies *should* be set ? We just screw them in to the press as per the instructions provided by Mr Lee and haven't had a problem... yet.  If there's a better way we'd like to learn.

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On 12/30/2020 at 9:37 AM, terryh said:

As per PbG,

’just enough’ FL resizing is IMHO the way to go. ie size to suit your chamber in your rifle. No need to smash back the brass to SAAMI/CIP minimum specs. 

I body size as a separate operation, just pushing the shoulder back a few thou.

Cannot see any advantage or reason to size any more than this or to ‘not’ do this.

T


ok, lots talking about bumping the the shoulder back. How would one do that? 
I take it I’d wind the die back further from the case holder, but how far?

to be honest, I can’t be doing much wrong, I’ve been shooting the same brass many many times, it’s still going strong. In my 308 it groups very well probably more by chance than anything else.

I need to spend time working a load for my 6.5. Although it’s performed well at 600 meters groups not great at 100. Not as good as my 308 anyway. So I need to experiment.


I have a fancy match die for that but didn’t realise you had to buy a separate part for the neck tensions so I keep using my cheap Lee die. I suppose I need to look there  first before I look into bumping shoulders.

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Hi....you bump the shoulders back by using either a full length sizing die, which as it infers resizes the whole case, including the neck, back to SAAMI spec, or a body die which resizes only the body of the case bumping the shoulders back but not resizing the neck. The further you screw the full length die down into the press relative to the shell holder it will resize more of the neck & bump the shoulders back further. Likewise the body die, the further you screw the die down into the press the more it will bump the shoulder back. You should be aware that with standard bottle neck cases what you are doing in fact is adjusting the headspace. You can tweak the amount of sizing by minor adjustments to the die. Moving a standard 7/8" die 1/8th of a turn is equal to 0.0089" of movement. However, once you have set your die into the press to the manufacturers instructions, some people like to adjust the bump by using Redding Competition shellholders to leave the die set as it is & adjust the bump/headspace accordingly with different size shell holders until the bolt locks down without any resistance with around 0.002"/0.003" clearance. They are sold in sets of 5 from +0.002" with incremental steps up to +0.010".........Whatever method you use it is best to measure what your cases relative to SAAMi specs measure once your brass has fire formed to your chamber 3-4 times. Then bumping back the shoulders circa 0.002" will ensure that you will avoid a "sticky bolt" & work your brass less extending your case life. There are many theories around this subject as I'm sure you will find with some saying that there is no evidence that over sizing your brass each time is detrimental to case life, but it just seems logical to me..... that's just my opinion for what it's worth.

You did not say what type of die your fancy match die is?.......If it is say a Redding Type S or Competition die bushing die then you will have to purchase the appropriate size bushing to achieve the optimum neck tension for the calibre/brass you are using.

Hope that helps.....

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Simples really.

Take your bolt out, remove the firing pin/striker and remove the ejector too. It’s fine to keep the extractor claw.

Screw your F/L die into your press until it contacts your shell holder. Now back the die out a couple of turns, so it won’t fully size all of the case back down to SAMMI spec as that’s too much.

Now insert your bolt (minus the firing pin/striker and ejector you removed) and the handle should just flop down without any resistance.

Take a piece of fired brass, lube it, place in press and size it. Remove brass, wipe lube off and place brass into your rifle’s chamber and gently close the bolt. If the bolt doesn’t fully close, or it closes with some force/resistance, the brass needs to be sized down further.

Extract brass, lube and place in press. Turn die DOWN (so sizing the brass more) just a tad (0.01 or 0.02). Size the brass again. Now try it again in your chamber.

Repeat just until your bolt will flop down like it did with no brass. This tell you that you’ve bumped your shoulder back just enough so the brass has minimal clearance but is guaranteed to chamber freely so you don’t get chambering issues. It’s also been sized just a minimal amount, no where near SAMMI spec. Use your calipers and Hornady headspace gauge to record the optimum headspace bump value.

Ive found this to be the most accurate way of measuring my chamber headspace and minimum case bump required.

There was an excellent and simple vid from Aron Wheeler (gunsmith) showing it all but I cannot find it on YouTube sadly.

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17 minutes ago, Catch-22 said:

Simples really.

Take your bolt out, remove the firing pin/striker and remove the ejector too. It’s fine to keep the extractor claw.

Screw your F/L die into your press until it contacts your shell holder. Now back the die out a couple of turns, so it won’t fully size all of the case back down to SAMMI spec as that’s too much.

Now insert your bolt (minus the firing pin/striker and ejector you removed) and the handle should just flop down without any resistance.

Take a piece of fired brass, lube it, place in press and size it. Remove brass, wipe lube off and place brass into your rifle’s chamber and gently close the bolt. If the bolt doesn’t fully close, or it closes with some force/resistance, the brass needs to be sized down further.

Extract brass, lube and place in press. Turn die DOWN (so sizing the brass more) just a tad (0.01 or 0.02). Size the brass again. Now try it again in your chamber.

Repeat just until your bolt will flop down like it did with no brass. This tell you that you’ve bumped your shoulder back just enough so the brass has minimal clearance but is guaranteed to chamber freely so you don’t get chambering issues. It’s also been sized just a minimal amount, no where near SAMMI spec. Use your calipers and Hornady headspace gauge to record the optimum headspace bump value.

Ive found this to be the most accurate way of measuring my chamber headspace and minimum case bump required.

There was an excellent and simple vid from Aron Wheeler (gunsmith) showing it all but I cannot find it on YouTube sadly.

This is very true.

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I’d add that a piece of brass that’s been sized twice will be slightly different to a piece of brass sized in one operation so confirm with another case. 

minimal difference really but when you’re talking such small sizing amounts ie 1 or 2 thou, it does matter. 

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8 minutes ago, furrybean said:

I’d add that a piece of brass that’s been sized twice will be slightly different to a piece of brass sized in one operation so confirm with another case. 

minimal difference really but when you’re talking such small sizing amounts ie 1 or 2 thou, it does matter. 

I have found this too,  I find a 'one operation' sizing confirmation is useful once the above (excellently described) procedures are done.

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Well if you want to be really specific its best to try several sized cases as each will probably be slightly different (more or less spring back even if annealed) and opt for the average but we are probably talking less than 0.001" here and the ability to consitently and accurately measure that difference starts to get difficult.

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19 hours ago, DeLaRue said:

Hi....you bump the shoulders back by using either a full length sizing die, which as it infers resizes the whole case, including the neck, back to SAAMI spec, or a body die which resizes only the body of the case bumping the shoulders back but not resizing the neck. The further you screw the full length die down into the press relative to the shell holder it will resize more of the neck & bump the shoulders back further. Likewise the body die, the further you screw the die down into the press the more it will bump the shoulder back. You should be aware that with standard bottle neck cases what you are doing in fact is adjusting the headspace. You can tweak the amount of sizing by minor adjustments to the die. Moving a standard 7/8" die 1/8th of a turn is equal to 0.0089" of movement. However, once you have set your die into the press to the manufacturers instructions, some people like to adjust the bump by using Redding Competition shellholders to leave the die set as it is & adjust the bump/headspace accordingly with different size shell holders until the bolt locks down without any resistance with around 0.002"/0.003" clearance. They are sold in sets of 5 from +0.002" with incremental steps up to +0.010".........Whatever method you use it is best to measure what your cases relative to SAAMi specs measure once your brass has fire formed to your chamber 3-4 times. Then bumping back the shoulders circa 0.002" will ensure that you will avoid a "sticky bolt" & work your brass less extending your case life. There are many theories around this subject as I'm sure you will find with some saying that there is no evidence that over sizing your brass each time is detrimental to case life, but it just seems logical to me..... that's just my opinion for what it's worth.

You did not say what type of die your fancy match die is?.......If it is say a Redding Type S or Competition die bushing die then you will have to purchase the appropriate size bushing to achieve the optimum neck tension for the calibre/brass you are using.

Hope that helps.....


yes it does,  thanks, makes sense

Hornady match I think they are. Yes I’ve found the part numbers. I just need to measure my brass to work out was bushing I need.

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