In Nancy's book Mid describes brass prep--his step 4 case sizing talks about use of a neck bushing and this I understand--what I don't understand is step 12--uniforming the case neck--he talks about using a mandrel to expand the case neck. Can anyone expound a bit on this--I don't have a mandrel--don't know where to get one and till now never heard of using one. Am I the only one who doesn't use a mandrel?
Mike
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Asa_Yam
Mike,
Having not read the book, here's a stab in the dark.
Uniforming the neck is done to ensure the following:
Concentricity of the finished round,
Uniform neck tension, and;
Allow for proper clearance between neck and chamber in a tight chamber.
To all of the items in 1) above, the mandrel expands the ID of the neck to a uniform diameter.
Outside turning then ensures items 1) a through c.
Sinclair International carries a variety of neck expanding mandrels.
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Kodiak
Mike,
A mandrel is a piece of high grade stainless steel that is used to expand the neck up and for neck turning and mandrels fit into a die body (Sinclair Expander Body - Sinclair cares 'em). There is different sized mandrel for the different calibers, 17, 22, 6, 25, 270, 7mm, 30, 8mm and 338. You FL size the brass without the expander button (moves the lumps to the inside of the case), then use the mandrel to move the lumps to the outside of the case, then neck turning cuts these lumps off. This mandrel is also the same piece of steel that fits into the neck turning tool (again see the Sinclair's catalog). They also sell an oversized mandrel for the neck up since the brass has a memory and once off the neck up mandrel and you use the neck turn smaller mandrel, it fits with less resistance.
Hope this helps, use this link
http://www.sinclairintl.com/cgi-bin/category.cgi
and search for mandrel
You will need some Imperial sizing die wax too or some Shooter's Choice FP-10 as a lube when neck turning, keep the mandrel from expanding from heat. When I neck turn, I measure to .0001" with a ball mic. Heat from your hands can also change the cutting depth!
Keith
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John Kelly
Depends what mandrel's being used.
Just to ride my favorite hobby horse again, I have found no device, die or bushing to prepare case necks with as little run out as a Lee collet die. Now, it uses a mandrel, only located at the lower end by the depriming pin through the flash hole, thus allowing the collet to reform the case neck about as concentrically as can be achieved - and that's internally to boot!
----------------------------------------------------------------------------------
STCLAIRMIKE
John another question--I do use a Redding neck bushing die and have had good results on uniformity and neck tension. Now after I run it through that die do I run it through the Lee Collet die? What happens to my neck tension that I just set with the Redding neck bushing die? Perhaps I am missing something but this goes back to my original question about the use of a mandrel--why do you need it if you have set the neck tension already with a neck bushing die? From my gages I have good uniformity already on my case necks.
Mike
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John Kelly
Mike,
I'm only talking about one caliber in my case - .308 Winchester - as I only shoot target & match rifle here in Australia. As I get all my work done by the one gunsmith, they all end up chambered with the same reamer, which is on the minimum tolerance end of the spectrum while staying SAAMI compliant.
OK, it's been my experience (or my prejudice) that only the Lee gives me uniformity without screwing up the case somewhere else, such that I can get by without shoulder bumping or any other fired case modification. When I used my Redding competition die with the necessary bushing for the Lapua brass I use, I felt that the neck was being concentric in, pushing the shoulder out a tad which necessitated a touch up with the resizer. With the Lee alone, cases could be returned straight back to the chamber & loaded without stressing the bolt, while other methods necessitated me taking that extra step, and I hate extra loading steps that I can avoid.
Apart from that, the Lee manages unturned necks fine, while I know I need to neck turn to get the best out of the Redding system & boy, do I hate neck turning. Apart from the distaste, turned brass is inevitably stressed more during firing in standard chambers as they are smaller in OD than the original brass & have to expand more. Anyway, I believe that you don't get the best out of turned brass unless you do it after at least the first firing, so why not prep the brass to accuracy standard from the word go?
Why the SAAMI chambering? Maybe I'll need to shoot factory ammunition some time - a shoot off or other such when I'm out of my own.
John
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BigDaddie
I actually use the Lee collet die to perform the mandrel job prior to neck turning. I adjust it so I get the right fit to the pilot on the neck turner.
On measuring, I have flat lining cases post turning and post firing and resizing so it must work the neck brass enough to push the lumpy bits to the outside for turning in the first place.
This has allowed me to get by without a sizing mandrel. However I am building a 6 dasher at the moment so I will need something like the Sinclair type mandrel in order to blueprint my brass post fire forming.
Just a quick question on these Sinclair mandrels, does anyone know what the ID ends up at for both 6mm & 30cal?
Cheers
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Clowdis
Mike,
I use my Redding full length sizer die to resize and deprime the case. Then I tumble the brass to get the lube off and then run them through a Lee Collet die to insure that the necks are straight and to the proper diameter inside. This makes the straightest brass I've ever had.
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Cessna
I have never used the Lee Collet Dies but I have been tempted to give one a try. All the other Lee dies I have used utilize a lock ring with a rubber O-ring in the bottom and no set screw to lock the ring against the die body. I have always replaced the lock rings with Forester/Bonanza rings so I can avoid changes in the die setting. Does the collet die use the same lock rings?
The O-ring allows the die to float a bit when the case is rammed into it. I think that this does result in better alignment between the case and the die and may be why there is little neck run out. I have eliminated this feature by changing the lock rings which may be a mistake on my part.
Steve Cass
Tucson
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Kevin Beggs
Cessna,
The Lee Collet die comes with the standard (O-ring) lock nuts. I too have replaced them but with RCBS rings.
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Mike Mills
In the portion of the section on reloading which I have read (not finished yet), the author describes using an expander mandrel just prior to neck turning.
This is done with a slightly oversized mandrel. The mandrel fits in a special die body and you run the brass up into the die/mandrel as a step in the neck turning operation.
The expanded neck can then slide over the regular sized mandrel for the neck turning operation. The extra few ten-thousandths, along with some lubrication, allow the case to more easily spin on the neck turning mandrel.
Without the use of the expander mandrel, the fit between the case and the neck turning mandrel is very tight and it takes more force to spin the case while neck turning.
As stated above, it is imperative to have the thickness irregularities on the outside of the case neck prior to neck turning. This is usually done with the expander ball (or a separate neck sizing mandrel if you use bushing dies without an expander ball).
The idea of using bushing dies without an expander ball and without neck turning doesn't make a lot of sense to me. This results in all the no uniformities ending up inside the case neck during bullet seating and using the bullet to push them out (or deforming the bullet around them). Nonetheless, I've read that some do it.
This post has been edited by Mike Mills: Dec 12 2006, 08:42 PM
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Ray Gross
QUOTE(Mike Mills @ Dec 12 2006, 07:36 PM)
The idea of using bushing dies without an expander ball and without neck turning doesn't make a lot of sense to me. This results in all the no uniformities ending up inside the case neck during bullet seating and using the bullet to push them out (or deforming the bullet around them). Nonetheless, I've read that some do it.
I do.
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Mike Mills
Why?
Or perhaps I should ask, why that as opposed to some other method?
Explain yourself, sir, this is a forum for communication.
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GUIDO
Mike,
If you use the expander mandrel on new brass it pushes the defects to the outside of the case neck and leaves you a nice round case mouth to chamfer before you seat a bullet. It also expands the ID of the neck to .0005-.001 under the diameter of the bullet. In doing this I don’t even use a neck die if I want .0005-.001 neck tension on my bullet. I f I want more tension I run the brass through my bushing neck die without the expander ball in it because the mandrel has already done the work. Same thing for fired brass. You are just taking the neck down so far with the bushing so you don’t need the expander ball like you do on standard dies that take the brass down so much they have to have an expander ball to take the neck back up so you can seat the bullet so the only way you can control your neck tension with these die is to use different diameter expander balls if you want to take it that far. So with Wilson or Redding competition dies use an expander mandrel as your first step in case prep because neither of these use expander balls. You owe me Ray ! I have blisters after that post !!
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Bob Joyce
Guido, do you have proof that the expander mandrel actually pushes an uneven thickness of the wall to the outside of the case neck? I've heard this before and have a problem understanding how the "defect" would move to the outside, at least completely. I haven't experimented with an expander mandrel but if I did, I would turn both the inside and outside of the case neck (after running the brass over the mandrel) to see exactly where the material is removed from. I would think that the inside of the case neck would still not be consistant, but would be improved.
Bob Joyce-CT
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Kodiak
If the full length die sizes the brass down, the outside of the brass is now smooth as the die itself. Now force the brass up via the mandrel, now the inside of the brass is now as smooth as the mandrel. You will see the un-even thickness in the shavings of the brass being cut off as you neck turn it off. You are cutting the high side of the neck off, and any lumps it may have. This gives you even neck tension as Asa_yam says, since you can hold the thickness of the necks to .0001" of your desired thickness, if you are careful.
Say no to inside neck reaming. All it does is clean up the inside of the necks, but does nothing to make the necks more concentric, that comes from the FL die. I have done both, inside reamed and outside neck turned and have been doing so for close to 20 years.
Inside reaming should only be done to take out a donut if it appears and only the donut, no more.
Like I said in my first post to this thread, even your hands holding the tool, as does the friction of the neck on the mandrel, increases the size of the mandrel itself and you end up removing more metal than you want. If you use power tools to neck turn, keep its RMP slow or things get hot fast.
SR Benchrest shooters only use 10-15 cases so neck turning is not too painful plus they have really tight chambers (most tight necked 6mm run around .262 to .265 and 30's run .330 to .335). Most long range BR shooter also neck turn and use tight necks, but again only limited number of cases.
Long range shooters need up to 120 rounds so this is why most use no turn necks, with 6mm running .272 and 30's running .342 or so. Large SAMMI is around .347 for a 30 I think. It's really really hard to make 120 cases exactly the same and your hands will be so sore after it is not funny.
I know, I have shot BR for many years and now LR for a few years. When I start LR, I used my BR rifles, now I have a no turn 6mm with a .2715 neck, but since it is a wildcat were the brass is made from a parent case and sized way down, I'm still neck turning.
The wind will do way more to your group’s size than having a loose case to chamber fitting does.
With the great 6BR brass and 308 Lapua brass, you really don't need to neck turn unless you have a tight necked chamber. This brass only varies a few 10 thou different per side.
If your brass varies a few thou per side with a good ball mic, like say .0121 to .148, like most American made brass(including Rem 308 URBR), then you may see a difference on the target, unless you index your brass marking the high side and always insert it in the chamber the same way, trouble with this method is over time the cases turn into bananas, but that is another topic. I'd neck turn myself until 60% to 70% of the neck is cut, more if I can. I like 100% cut necks.
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GUIDO
Mike, I just have never bought into the idea that imperfections are pushed into the ID and even if they are as long as I am getting uniform seating pressure (which may be a proxy for uniform neck tension) I am happy.
I may have some advantage in that I have a Ken Light Annealing machine and can uniformly anneal large quantities of brass regularly. It is surprising how variable seating pressure can become after five or six resizings. An occasional annealing softens the necks and I can definitely feel the difference while seating bullets into the re-annealed brass.
I really try to take a minimalist approach to reloading. I don't go the extra mile to cut my groups by a 1/4". I do what I need to do to produce sub 3/4 minute 10 shot groups at 600 yards with iron sights. With a good rifle you don't have to do much to accomplish that.
I have always believed that my score is 80% me, 10% rifle and 10% ammo. A little improvement on my part will have a substantially larger improvement on my score than a huge improvement in my ammo.
Mike
--------------------
Asa_Yam
Mike,
Having not read the book, here's a stab in the dark.
Uniforming the neck is done to ensure the following:
Concentricity of the finished round,
Uniform neck tension, and;
Allow for proper clearance between neck and chamber in a tight chamber.
To all of the items in 1) above, the mandrel expands the ID of the neck to a uniform diameter.
Outside turning then ensures items 1) a through c.
Sinclair International carries a variety of neck expanding mandrels.
-----------------------------------------------------------------------------------------------
Kodiak
Mike,
A mandrel is a piece of high grade stainless steel that is used to expand the neck up and for neck turning and mandrels fit into a die body (Sinclair Expander Body - Sinclair cares 'em). There is different sized mandrel for the different calibers, 17, 22, 6, 25, 270, 7mm, 30, 8mm and 338. You FL size the brass without the expander button (moves the lumps to the inside of the case), then use the mandrel to move the lumps to the outside of the case, then neck turning cuts these lumps off. This mandrel is also the same piece of steel that fits into the neck turning tool (again see the Sinclair's catalog). They also sell an oversized mandrel for the neck up since the brass has a memory and once off the neck up mandrel and you use the neck turn smaller mandrel, it fits with less resistance.
Hope this helps, use this link
http://www.sinclairintl.com/cgi-bin/category.cgi
and search for mandrel
You will need some Imperial sizing die wax too or some Shooter's Choice FP-10 as a lube when neck turning, keep the mandrel from expanding from heat. When I neck turn, I measure to .0001" with a ball mic. Heat from your hands can also change the cutting depth!
Keith
----------------------------------------------------------------------------------------------
John Kelly
Depends what mandrel's being used.
Just to ride my favorite hobby horse again, I have found no device, die or bushing to prepare case necks with as little run out as a Lee collet die. Now, it uses a mandrel, only located at the lower end by the depriming pin through the flash hole, thus allowing the collet to reform the case neck about as concentrically as can be achieved - and that's internally to boot!
----------------------------------------------------------------------------------
STCLAIRMIKE
John another question--I do use a Redding neck bushing die and have had good results on uniformity and neck tension. Now after I run it through that die do I run it through the Lee Collet die? What happens to my neck tension that I just set with the Redding neck bushing die? Perhaps I am missing something but this goes back to my original question about the use of a mandrel--why do you need it if you have set the neck tension already with a neck bushing die? From my gages I have good uniformity already on my case necks.
Mike
-----------------------------------------------------------------------------------
John Kelly
Mike,
I'm only talking about one caliber in my case - .308 Winchester - as I only shoot target & match rifle here in Australia. As I get all my work done by the one gunsmith, they all end up chambered with the same reamer, which is on the minimum tolerance end of the spectrum while staying SAAMI compliant.
OK, it's been my experience (or my prejudice) that only the Lee gives me uniformity without screwing up the case somewhere else, such that I can get by without shoulder bumping or any other fired case modification. When I used my Redding competition die with the necessary bushing for the Lapua brass I use, I felt that the neck was being concentric in, pushing the shoulder out a tad which necessitated a touch up with the resizer. With the Lee alone, cases could be returned straight back to the chamber & loaded without stressing the bolt, while other methods necessitated me taking that extra step, and I hate extra loading steps that I can avoid.
Apart from that, the Lee manages unturned necks fine, while I know I need to neck turn to get the best out of the Redding system & boy, do I hate neck turning. Apart from the distaste, turned brass is inevitably stressed more during firing in standard chambers as they are smaller in OD than the original brass & have to expand more. Anyway, I believe that you don't get the best out of turned brass unless you do it after at least the first firing, so why not prep the brass to accuracy standard from the word go?
Why the SAAMI chambering? Maybe I'll need to shoot factory ammunition some time - a shoot off or other such when I'm out of my own.
John
---------------------------------------------------------------------------------------------
BigDaddie
I actually use the Lee collet die to perform the mandrel job prior to neck turning. I adjust it so I get the right fit to the pilot on the neck turner.
On measuring, I have flat lining cases post turning and post firing and resizing so it must work the neck brass enough to push the lumpy bits to the outside for turning in the first place.
This has allowed me to get by without a sizing mandrel. However I am building a 6 dasher at the moment so I will need something like the Sinclair type mandrel in order to blueprint my brass post fire forming.
Just a quick question on these Sinclair mandrels, does anyone know what the ID ends up at for both 6mm & 30cal?
Cheers
--------------------------------------------------------------------------------------------
Clowdis
Mike,
I use my Redding full length sizer die to resize and deprime the case. Then I tumble the brass to get the lube off and then run them through a Lee Collet die to insure that the necks are straight and to the proper diameter inside. This makes the straightest brass I've ever had.
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Cessna
I have never used the Lee Collet Dies but I have been tempted to give one a try. All the other Lee dies I have used utilize a lock ring with a rubber O-ring in the bottom and no set screw to lock the ring against the die body. I have always replaced the lock rings with Forester/Bonanza rings so I can avoid changes in the die setting. Does the collet die use the same lock rings?
The O-ring allows the die to float a bit when the case is rammed into it. I think that this does result in better alignment between the case and the die and may be why there is little neck run out. I have eliminated this feature by changing the lock rings which may be a mistake on my part.
Steve Cass
Tucson
----------------------------------------------------------------------------------------------
Kevin Beggs
Cessna,
The Lee Collet die comes with the standard (O-ring) lock nuts. I too have replaced them but with RCBS rings.
--------------------------------------------------------------------------------------------
Mike Mills
In the portion of the section on reloading which I have read (not finished yet), the author describes using an expander mandrel just prior to neck turning.
This is done with a slightly oversized mandrel. The mandrel fits in a special die body and you run the brass up into the die/mandrel as a step in the neck turning operation.
The expanded neck can then slide over the regular sized mandrel for the neck turning operation. The extra few ten-thousandths, along with some lubrication, allow the case to more easily spin on the neck turning mandrel.
Without the use of the expander mandrel, the fit between the case and the neck turning mandrel is very tight and it takes more force to spin the case while neck turning.
As stated above, it is imperative to have the thickness irregularities on the outside of the case neck prior to neck turning. This is usually done with the expander ball (or a separate neck sizing mandrel if you use bushing dies without an expander ball).
The idea of using bushing dies without an expander ball and without neck turning doesn't make a lot of sense to me. This results in all the no uniformities ending up inside the case neck during bullet seating and using the bullet to push them out (or deforming the bullet around them). Nonetheless, I've read that some do it.
This post has been edited by Mike Mills: Dec 12 2006, 08:42 PM
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Ray Gross
QUOTE(Mike Mills @ Dec 12 2006, 07:36 PM)
The idea of using bushing dies without an expander ball and without neck turning doesn't make a lot of sense to me. This results in all the no uniformities ending up inside the case neck during bullet seating and using the bullet to push them out (or deforming the bullet around them). Nonetheless, I've read that some do it.
I do.
---------------------------------------------------------------------------------------------
Mike Mills
Why?
Or perhaps I should ask, why that as opposed to some other method?
Explain yourself, sir, this is a forum for communication.
-----------------------------------------------------------------------------------------------
GUIDO
Mike,
If you use the expander mandrel on new brass it pushes the defects to the outside of the case neck and leaves you a nice round case mouth to chamfer before you seat a bullet. It also expands the ID of the neck to .0005-.001 under the diameter of the bullet. In doing this I don’t even use a neck die if I want .0005-.001 neck tension on my bullet. I f I want more tension I run the brass through my bushing neck die without the expander ball in it because the mandrel has already done the work. Same thing for fired brass. You are just taking the neck down so far with the bushing so you don’t need the expander ball like you do on standard dies that take the brass down so much they have to have an expander ball to take the neck back up so you can seat the bullet so the only way you can control your neck tension with these die is to use different diameter expander balls if you want to take it that far. So with Wilson or Redding competition dies use an expander mandrel as your first step in case prep because neither of these use expander balls. You owe me Ray ! I have blisters after that post !!
----------------------------------------------------------------------------------------------
Bob Joyce
Guido, do you have proof that the expander mandrel actually pushes an uneven thickness of the wall to the outside of the case neck? I've heard this before and have a problem understanding how the "defect" would move to the outside, at least completely. I haven't experimented with an expander mandrel but if I did, I would turn both the inside and outside of the case neck (after running the brass over the mandrel) to see exactly where the material is removed from. I would think that the inside of the case neck would still not be consistant, but would be improved.
Bob Joyce-CT
----------------------------------------------------------------------------------------------
Kodiak
If the full length die sizes the brass down, the outside of the brass is now smooth as the die itself. Now force the brass up via the mandrel, now the inside of the brass is now as smooth as the mandrel. You will see the un-even thickness in the shavings of the brass being cut off as you neck turn it off. You are cutting the high side of the neck off, and any lumps it may have. This gives you even neck tension as Asa_yam says, since you can hold the thickness of the necks to .0001" of your desired thickness, if you are careful.
Say no to inside neck reaming. All it does is clean up the inside of the necks, but does nothing to make the necks more concentric, that comes from the FL die. I have done both, inside reamed and outside neck turned and have been doing so for close to 20 years.
Inside reaming should only be done to take out a donut if it appears and only the donut, no more.
Like I said in my first post to this thread, even your hands holding the tool, as does the friction of the neck on the mandrel, increases the size of the mandrel itself and you end up removing more metal than you want. If you use power tools to neck turn, keep its RMP slow or things get hot fast.
SR Benchrest shooters only use 10-15 cases so neck turning is not too painful plus they have really tight chambers (most tight necked 6mm run around .262 to .265 and 30's run .330 to .335). Most long range BR shooter also neck turn and use tight necks, but again only limited number of cases.
Long range shooters need up to 120 rounds so this is why most use no turn necks, with 6mm running .272 and 30's running .342 or so. Large SAMMI is around .347 for a 30 I think. It's really really hard to make 120 cases exactly the same and your hands will be so sore after it is not funny.
I know, I have shot BR for many years and now LR for a few years. When I start LR, I used my BR rifles, now I have a no turn 6mm with a .2715 neck, but since it is a wildcat were the brass is made from a parent case and sized way down, I'm still neck turning.
The wind will do way more to your group’s size than having a loose case to chamber fitting does.
With the great 6BR brass and 308 Lapua brass, you really don't need to neck turn unless you have a tight necked chamber. This brass only varies a few 10 thou different per side.
If your brass varies a few thou per side with a good ball mic, like say .0121 to .148, like most American made brass(including Rem 308 URBR), then you may see a difference on the target, unless you index your brass marking the high side and always insert it in the chamber the same way, trouble with this method is over time the cases turn into bananas, but that is another topic. I'd neck turn myself until 60% to 70% of the neck is cut, more if I can. I like 100% cut necks.
-----------------------------------------------------------------------------------------------
GUIDO
Mike, I just have never bought into the idea that imperfections are pushed into the ID and even if they are as long as I am getting uniform seating pressure (which may be a proxy for uniform neck tension) I am happy.
I may have some advantage in that I have a Ken Light Annealing machine and can uniformly anneal large quantities of brass regularly. It is surprising how variable seating pressure can become after five or six resizings. An occasional annealing softens the necks and I can definitely feel the difference while seating bullets into the re-annealed brass.
I really try to take a minimalist approach to reloading. I don't go the extra mile to cut my groups by a 1/4". I do what I need to do to produce sub 3/4 minute 10 shot groups at 600 yards with iron sights. With a good rifle you don't have to do much to accomplish that.
I have always believed that my score is 80% me, 10% rifle and 10% ammo. A little improvement on my part will have a substantially larger improvement on my score than a huge improvement in my ammo.
