SCSCHNUR
Well-Known Member
Use redding body die and LE Wilson expanding mandrel die.
Neck expansion
- Thread starter nksmfamjp
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CTK
Well-Known Member
Awesomeness.........
ntsqd
Well-Known Member
I invested in the Sinclair expander die and I've only just begun to use it, but since that purchase I found out about the Kenny Porter die and I will be replacing the Sinclair system.
DUSTY NOGGIN
Well-Known Member
less uneeded movememt that smears brass and causes runout .
creates different spring back tensions form neck to neck of different brass
the thickness of necks vary and full length is built in tolerance that it will down size and back upsize no matter how thick the brass necks are .. thick necks have to move more sometime as much as .010 .. which works it way more than needed
if you are feeling different pressures while seating probably should try bushings dies and expanding ..
Using Lapua or Norma brass with my FL Redding competition dyes/bushing with .00015-.002" of neck tension, I have not found the need to expand the necks after sizing. I have not had issues with consistent neck tension, runout, or ES I will use an expander with new, unfired brass to bring the neck up to my desired tension.
nksmfamjp
Well-Known Member
- Joined
- Jan 5, 2004
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- 3,354
So, there seems to be several Redding type S users in here. Many post about using a separate mandrel for concentricity, but the Redding expander button is on a thick rod and free floats...I would think I couldn't do better, unless I had too small of a bushing. Is that good logic?
i also have a k&m mandrel to try.
i also have a k&m mandrel to try.
Varmint Hunter
Well-Known Member
I really enjoy reloading but there is only so much time in the day. I do what I find meets my accuracy criteria and no more. All of my hunting rifles will shoot .5moa at 400yds. Not ALWAYS but most of the time once a preferred load has been developed.
I use Redding type S FL dies and an appropriate size bushing. It pays to have a variety of bushings on hand so that neck tension can be changed if you feel a need to. I do not use an expander mandrel, never saw a need to.
BTW - I no longer weigh my brass but do use high quality brass whenever available. I do not sort bullets by bearing length. I don't weigh primers, don't anneal my brass and don't fret over the small stuff. None of this is necessary to get consistent 1/2 moa ammo providing that you are careful in your reloading technique and systematically develop a load that works in your rifle. Naturally, you will need an accurate rifle to begin with.
I use Redding type S FL dies and an appropriate size bushing. It pays to have a variety of bushings on hand so that neck tension can be changed if you feel a need to. I do not use an expander mandrel, never saw a need to.
BTW - I no longer weigh my brass but do use high quality brass whenever available. I do not sort bullets by bearing length. I don't weigh primers, don't anneal my brass and don't fret over the small stuff. None of this is necessary to get consistent 1/2 moa ammo providing that you are careful in your reloading technique and systematically develop a load that works in your rifle. Naturally, you will need an accurate rifle to begin with.
Mikecr
Well-Known Member
So now we're going to the benefits of neck expansion, and mandrel expansion.
If you were to research back 20yrs+ you would find that I was the first person to suggest mandrel neck expansion. And, you would see that everyone thought it was a stupid notion. Why do this operation at all, much less separate?
I'm sure today, still, many reloaders are not inclined to bother with it.
Part of it goes to the common misunderstanding of what neck tension is.
People still think it's interference fit with bullet seating. More interference, higher seating forces, equals higher neck tension (even while partial neck sizing). That never was, and never will be true.
When you leave necks in high interference with seating bullets, you're merely using your bullets for neck expansion. It's not good for your bullets, for consistent CBTO, and it overly work hardens necks.
When you pull a seated bullet, that you just expanded a neck with, that neck springs back ~1/2thou. Doesn't matter how much you downsize it(beyond spring back), after seating a bullet & pulling it, necks spring back to ~1/2thou under cal (interference).
Now, using a mandrel, you can perform a 'pre-seating' operation that removes neck expansion from a bullet's duty.
Expansion being sizing, and sizing is that causing yielding.
Ideally the mandrel would be at cal (like a bullet), and this would leave necks in spring back interference (under cal), just as bullet seating would.
Tension is the spring back force that is gripping an area of seated bullet bearing. It is pounds per square inch (PSI). You should be adjusting this through LENGTH (area) of bushing sizing, to no more than seated bearing.
The bushing size needs only to produce prerequisite interference for effective neck expansion. This is often set 2thou under cal as a rule. Close enough.
You can go more or less with what you have, just keep in mind that it is beyond ideal. It isn't helping, only hurting.
I'm outta time, but tonight I'll lay out a couple more important aspects of expansion.
If you were to research back 20yrs+ you would find that I was the first person to suggest mandrel neck expansion. And, you would see that everyone thought it was a stupid notion. Why do this operation at all, much less separate?
I'm sure today, still, many reloaders are not inclined to bother with it.
Part of it goes to the common misunderstanding of what neck tension is.
People still think it's interference fit with bullet seating. More interference, higher seating forces, equals higher neck tension (even while partial neck sizing). That never was, and never will be true.
When you leave necks in high interference with seating bullets, you're merely using your bullets for neck expansion. It's not good for your bullets, for consistent CBTO, and it overly work hardens necks.
When you pull a seated bullet, that you just expanded a neck with, that neck springs back ~1/2thou. Doesn't matter how much you downsize it(beyond spring back), after seating a bullet & pulling it, necks spring back to ~1/2thou under cal (interference).
Now, using a mandrel, you can perform a 'pre-seating' operation that removes neck expansion from a bullet's duty.
Expansion being sizing, and sizing is that causing yielding.
Ideally the mandrel would be at cal (like a bullet), and this would leave necks in spring back interference (under cal), just as bullet seating would.
Tension is the spring back force that is gripping an area of seated bullet bearing. It is pounds per square inch (PSI). You should be adjusting this through LENGTH (area) of bushing sizing, to no more than seated bearing.
The bushing size needs only to produce prerequisite interference for effective neck expansion. This is often set 2thou under cal as a rule. Close enough.
You can go more or less with what you have, just keep in mind that it is beyond ideal. It isn't helping, only hurting.
I'm outta time, but tonight I'll lay out a couple more important aspects of expansion.
Varmint Hunter
Well-Known Member
MIkecr,
I don't disagree with your methods or the outcome that you achieve. My post merely recognizes that not everyone seeks the same level of precision or has the time, equipment, knowledge or dedication to achieve the extreme degree of precision that others strive for.
For me, I'm a hunter that keeps his biggame kills within 500yds. I use good components and have developed reloading methods which will maintain .5moa, which is far better than I need. The .5moa is merely a confidence builder because I can't hold within .5moa when shooting under field conditions.
I admire all the true longrange hunters that post here and have learned from those who take the time to share their experiences.
I don't disagree with your methods or the outcome that you achieve. My post merely recognizes that not everyone seeks the same level of precision or has the time, equipment, knowledge or dedication to achieve the extreme degree of precision that others strive for.
For me, I'm a hunter that keeps his biggame kills within 500yds. I use good components and have developed reloading methods which will maintain .5moa, which is far better than I need. The .5moa is merely a confidence builder because I can't hold within .5moa when shooting under field conditions.
I admire all the true longrange hunters that post here and have learned from those who take the time to share their experiences.
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ntsqd
Well-Known Member
See if I understand what Mike CR is saying from my engineering back-ground frame of reference.
Greater interference fit between the neck and the bullet would result in more neck tension IF the bullet was not compressible/distortable at this force level, but because the bullet IS compressible/distortable at this force level what happens is that some sort of equilibrium between neck tension and bullet distortion is achieved. This equilibrium happens at the normal max neck tension, which is the Spring-back force. Which means that the bullet has been altered considerably. In an undesirable direction.
Greater interference fit between the neck and the bullet would result in more neck tension IF the bullet was not compressible/distortable at this force level, but because the bullet IS compressible/distortable at this force level what happens is that some sort of equilibrium between neck tension and bullet distortion is achieved. This equilibrium happens at the normal max neck tension, which is the Spring-back force. Which means that the bullet has been altered considerably. In an undesirable direction.
Mikecr
Well-Known Member
No, you're not compressing bullets with neck tension.
The squeeze on bullets(what grips them) is no more than brass spring back force(hoop tension) against an area.
It is not much, taking relatively low PSI to overcome, and just the slightest expansion(any) fully releases bullets.
Where bullets are damaged from excess seating forces, that damage would likely occur to the ogive(where the force is applied).
Cartridge brass yields with any dimension change exceeding it's spring back(~1/2thou). This is a point of diminished returns(a plateau) for spring back.
Picture over-tightening of a bolt. When it yields (goes plastic) the turning/tightening force no longer goes up, and the experienced know right there that the bolt is going to snap with continued turning(well before it actually does).
Once you've taken brass to yield, extra energy/travel from there serves only to form new dimension. It does not add more spring back, so that it could recover from that new form.
In other words, you're just sizing and not increasing tension.
The squeeze on bullets(what grips them) is no more than brass spring back force(hoop tension) against an area.
It is not much, taking relatively low PSI to overcome, and just the slightest expansion(any) fully releases bullets.
Where bullets are damaged from excess seating forces, that damage would likely occur to the ogive(where the force is applied).
Cartridge brass yields with any dimension change exceeding it's spring back(~1/2thou). This is a point of diminished returns(a plateau) for spring back.
Picture over-tightening of a bolt. When it yields (goes plastic) the turning/tightening force no longer goes up, and the experienced know right there that the bolt is going to snap with continued turning(well before it actually does).
Once you've taken brass to yield, extra energy/travel from there serves only to form new dimension. It does not add more spring back, so that it could recover from that new form.
In other words, you're just sizing and not increasing tension.
ntsqd
Well-Known Member
OK, I see that. Elastic deformation is ~.0005" after which it goes into plastic deformation. You're always going to have that elastic deformation no matter how far you move it in plastic. This is assuming no or very little pre-existing work hardening etc. which would change the stress-strain curve to where the plastic deformation may cause a crack.
My expander does not free float. Redding type S fl bushing die.
As the expander comes out of the lubed bushing sized neck, light drag should be felt as the expander opens the necks. Unturned brass. Neck turned needs no expander. Imo.
Reddings website will tell you sizing fired necks down more then .008" in 1 step may cause runout problems. The target will tell you.
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DUSTY NOGGIN
Well-Known Member
conside the shoulder angle bump spring back also .. if bumped . which way does it wanna spring back .. now anneal one .. how far does it wanna spring back now . then decide which way you want to expand from , dragging tnrough or pushing in .. which way do you supposed gives the most relaxed state at the dimension .
when one side of the neck is thicker does one think that is would deform more on one side that the other enough to create runout .. and would it do the same thing if annealed ??
some arguments here are starting with different brass which needs ro be shaped differently
when one side of the neck is thicker does one think that is would deform more on one side that the other enough to create runout .. and would it do the same thing if annealed ??
some arguments here are starting with different brass which needs ro be shaped differently
