I have different die sets for some of the same calibers I reload for. After measuring the case neck on some finished rounds I noted that some die sets would put more case neck tension [The outside diameter would be slightly smaller] on the bullet than others.

Does it matter that much? I ask because on one of the calibers I am reloading I was thinking of buying the Redding Bushing style die sets.

I have seen tests where different case neck tension is significant starting at about 300yards and beyond, so for the long range shooter, and the bench rest guy that wants one holers the simply answer is yes.

If most of your shots are between 100 to 200 yards and you are mostly hunting then I would say no.

I have the bushing die set for my 6.5mm. I don't use it for my 22-250, 220 swifts, 243,or 7mm that I hunt with.

Varying case neck tension is one of the harder things to get rid of in reloading. It can arise from several sources, including different die dimensions (if you use a regular sizing die, the diameter of the expander ball is one important factor), different brass manufacture, different brass lots and even the number of times a case has been resized (work hardening) or how long ago it was since the case was sized!

Does it matter?? I believe it definitely produces a noticeable effect if you shoot groups with accurate (competition type) rifles. There is no doubt in my mind about this.

Does it matter for hunting rifles?? Probably not if you expect the effect to cause a difference between .7" and .9" groups - either of which is beyond relevance for hunting.

If you consider buying dies, which will directly allow you to influence the amount of neck tension you produce - e.g. Redding bushing dies - be aware, that it has been my experince that the recommendations from Redding of using very low neck tension values have not turned out as positive as I had expected. I have come to believe, that if you really want to rely on such low neck tension figures (typically .001" - .002" below loaded round neck diameter), you have to control your brass by neck turning and/or annealing. If you don't, you are pissing into the wind, and the effects of varying neck tension will be more noticeable because you work with such low nominal numbers.

Even in BR (in particular shooting the 6mm PPC with N133) more neck tension has proven to be an advantage. Typically, you see values used from .002-.004".

I think one of the reasons die manufacturers like to recommend such low neck tension figures, is that bushing dies have a nasty tendency to create runout. This effect, however, can be minimized if you size the brass less - i.e. create less neck tension. So by trying to control one issue (tension), you may have run straight into the next (runout). The better alternative (although not as flexible as a bushing die) is to use a die with a fixed internal neck diameter, to allow you to size without an expander. Alternatively, I have heard some of the custom dies used by the BR crowd allow bushings to be fixed in the die neck - something the Redding bushings does not easily allow.

- mike

quote:

Originally posted by RenegadeRN:
[The outside diameter would be slightly smaller] on the bullet than others.

If the OUTSIDE diameter of your necks vary AFTER the bullet is seated, then it has nothing to do with your dies or "case neck tension". The outside diameter is controlled by the diameter of the bullet plus the thickness of the case neck walls. No matter how small your resizing die may leave the neck, it will always be the same size after seating the bullet.

A significant variation in outside case neck diameters can only mean a signficant variation in the thickness of the case necks. Are you comparing two different brands or lots of brass? Or perhaps brass that has been fired several times, as case necks can thicken as firing and resizing causes brass to flow forward.

I used two separate die sets for .330 WIN Mag. I used the same bullets by manufacturer in the same weight, same brass, etc. The outside diameter of the neck of one round loaded on die manufacturer 1 was about .002-.003 smaller than the outside neck diameter of the neck of die manufacturer 2. It was consistent across the board.

I realize we are talking fine hairs here...just wondering is all. And I think everyone answered my questions. One die set is a basic set while the other die set is supposedly benchrest type by name. I guess the only way to find out is to try both types of rounds. LOL! Its all a learning experience to say the least.

ARGGH...why does my ring finger on my left hand ALWAYS hit that extra three instead of the 0 on my right hand? I meant .300 WIN MAG vice .330 Win Mag.

mho, that's about the best explanation I have ever read. Thanks for posting that.

The only thing I could add is that runout can be reduced with bushing dies if you use two or more bushings and gradually reduce the neck. To me this is a pain in the ass. That's why I start with a Lee Collet die and finish with a Redding bushing die without the expander. Keeps runout to a minimum.

Stonecreek got it right. The only 2 things that will control the outside neck diameter of a loaded round will be the outside diameter of the bullet and the thickness of the neck wall, period.

I also agree with mho that bushing dies have a nasty habit of creating runout. I have switched to Lee Collets and I sent off for and received mandrels that are undersized from .002" to .004" ($5.00 each). Plan to do some tests this winter to see what effect the greater neck tension will have.

quote:

Originally posted by woods:
Stonecreek got it right. The only 2 things that will control the outside neck diameter of a loaded round will be the outside diameter of the bullet and the thickness of the neck wall, period.

Well, Woods, maybe not. If Renegade is consistently getting one .002-3 larger than the other, maybe the bullet is .002-3 short of touching the neck walls on the larger one. I'm not sure how it stays in place if that's the case; magnetic levitation maybe?

quote:

Originally posted by steve4102:
The only thing I could add is that runout can be reduced with bushing dies if you use two or more bushings and gradually reduce the neck. To me this is a pain in the ass. That's why I start with a Lee Collet die and finish with a Redding bushing die without the expander. Keeps runout to a minimum.

That would make a lot of sense. It points to the runout being a sideeffect of how much the brass is moved. In effect, that is exactly what Redding is indicating, when they suggest using .001-.002" neck tension to avoid runout.

My preferred die set-up is a Forster FL die modified to a fixed internal neck diameter and the expander ball removed. That way I can size my cases in a single operation (including decapping), and get next to no runout. The drawback of this setup, is that you have to decide on the neck tension you want to use in advance. It does not allow you to experiment like bushing dies do.

- mike

quote:

Originally posted by mho:


My preferred die set-up is a Forster FL die modified to a fixed internal neck diameter and the expander ball removed. That way I can size my cases in a single operation (including decapping), and get next to no runout. The drawback of this setup, is that you have to decide on the neck tension you want to use in advance. It does not allow you to experiment like bushing dies do.

- mike

Hey mike

Doesn't that also mean you have to turn the necks in order to get a consistant inside neck diameter and thus consistant bullet release?

What is better:

• A consistant inside neck diameter with all the inconsistancies and all the runout due to varying neck thickness on the outside of the neck (where it doesn't matter)
  
• A consistant outside neck diamter with all the inconsistancies and all the runout due to varying neck thickness on the inside of the neck (where it can affect bullet release)

Or am I missing something and this is not what is happening with the honed out Forster Die?

Woods,

if one is looking for the optimal in consistency and accuracy, it is probably not a bad idea to control case neck variations. Neck turning is the ultimate way of doing this - more and more BR shooters turn not to reduce neck wall thickness but to control wall variation.

For people like myself who are too "lazy" to turn necks, sorting cases according to neck wall variation is probably the next best thing. I use the Sinclair Neck Wall Thickness Gauge for this purpose (http://www.sinclairintl.com/cgi-bin/category.cgi?catego...tem=MIC-4&type=store). Depending on what the application of the caliber is (target or hunting, say) I may accept different variations. Inaccptable cases are relegated to "fowler" status.

Annealing cases to attempt to control work hardening is probably also a good thing.

In Glen Zediker's book "Reloading for Competition" (http://www.sinclairintl.com/cgi-bin/category.cgi?catego...em=15-845&type=store), he also discusses the issue of whether case inconsistencies are located on the inside or the outside of the case necks - i.e. the differences between using some sort of an expander or not. I choose NOT to use an expander and thus live with inconsistencies on the inside of the neck wall.

Will this give me inconsistent bullet release?? I don't know, but I do know I use fairly high neck tensions (.003-.005") and that to a certain extent hides inconsistencies due to wall variations.

To me it is essentially a matter of balancing the advantages vs the disadvantages in the use of an expander. I ended up in the non-expander camp and earn very straight cases for my efforts. I try to minimize the drawbacks of neck wall inconsistency as I described above.

I can't state there is not a better way to do this - perhaps using a combination of neck inside and expander dimensions that will avoid the expander moving the brass very much (more or less just "smoothing" out inside necks). It would be interesting to try out. In the meantime, I'm quite happy with the results I get from my honed Forster dies. It took me a while to arrive at this technique - the road led via standard dies, Collet dies, Redding Bushings and finally the Forsters... Perhaps I'll be somewhere else in a couple of years (sigh - another 20-30 die sets to purchase )??

- mike

I was loading some Barnes TSX bullets some of which were so loose in the neck one could easily turn them by hand. I decided to shoot them and compare the accuracy with firmly seated bullets. The ones that were loose shot the best.

I also shot some bench rest with a guy who was quite good; went to "Super Shoot," etc. For the 5 shot strings, he would reload the same 5 cases on the bench and seat the bullets by hand. The bullets were loose in the case. Since he usually shot 1 hole 5 shot groups at 100 yards, I would conclude that increasing neck tension probably wouldn't have benefited him.

Compared to 45,000 to 65,000 psi pushing a bullet down the barrel, neck tension is insignificant.

Grumulkin,

I don't keep up with benchrest shooting fashions much any more, but it used to be popular to undersize the chamber's neck and thin the upper neck walls so that an inside "step" could be created near the base of the neck of the brass. The brass would be reused without any resizing with the bullet simply slid into place until the heel was bearing against the inside step. This would control seating depth, but otherwise the bullet was simply a slip-fit. Impractical for hunting, of course, but apparently very conducive to accuracy.

quote:

Originally posted by Grumulkin:
For the 5 shot strings, he would reload the same 5 cases on the bench and seat the bullets by hand. The bullets were loose in the case. Since he usually shot 1 hole 5 shot groups at 100 yards, I would conclude that increasing neck tension probably wouldn't have benefited him.

There are all sorts of ways people get good results. However, the BR guys in here (Butch Lambert et al) may confirm that the current "vogue" in BR reloading the 6PPC goes in the direction of FL sizing (or shoulder "bumping") and quite a bit of neck tension - at least if you are shooting N133.

For a while "fitted" necks were very popular in BR as well. Those cases fit so closely in the chamber they did not even have to be resized. I'm sure there are people who still apply this technique, but it is probably not the majority of BR shooters.

- mike

quote:

Originally posted by mho:
I choose NOT to use an expander and thus live with inconsistencies on the inside of the neck wall.

Will this give me inconsistent bullet release?? I don't know, but I do know I use fairly high neck tensions (.003-.005") and that to a certain extent hides inconsistencies due to wall variations.

To me it is essentially a matter of balancing the advantages vs the disadvantages in the use of an expander. I ended up in the non-expander camp and earn very straight cases for my efforts. I try to minimize the drawbacks of neck wall inconsistency as I described above.


- mike

Hey mike

I'm with you on the "no expander ball" team.

Seems to me that you can size without an expander and still have the inconsistancies and runout on the outside of the neck, with the Lee Collet Neck Sizer. Is there a particular reason you chose not to use the Lee Collet? Did you try the Lee Collet?

I'm not sure that it makes that much difference whether the inside or the outside of the neck is smooth but it seems to me that pushing the problems all to the inside is just hiding them.

I don't understand this runout issue with bushing type dies. Why does a bushing type die produce more runout than a regular die (both w/o expander of course).

I am currently experimenting with different neck tensions (with vs. w/o expander) myself and my theory is very close to that of Mike's.

If I reduce the neck's inner diameter far enough for the bullet to take over the part of the expander ball, I should get the same result as with the employment of an expander, but without the negative result of runout by stretching.

Woods, I do use Collet dies. I used to use them for all my calibers, but I liked the setup of the honed Forster so much that I'm gradually moving in that direction. Less than optimal finances have restricted me from getting Forsters for all my rifles...

The Collets offer amazing value for the money, but they can be a bit fiddly to get to work. I don't find the sizing operation as smooth as it is with the Forsters, and I like chambering (P)FL sized cases. So I gravitate towards the FL Fosters. On the plus side for the Collets, they don't require cases to be lubed for sizing, that is practical!

quote:

Originally posted by McFox:
I don't understand this runout issue with bushing type dies. Why does a bushing type die produce more runout than a regular die (both w/o expander of course).

MF, I don't know. I only relate what I have observed. It seems, though, that I'm far from the only reloader having made this observation. Check out this discussion over on benchrest.com:

http://benchrest.com/forums/showthread.php?t=44695

In particular the following couple of replies:

quote:

Originally posted by BJS6:
Mr Weldy,

While my testing/observations have been by no means exhaustive and I am no authority at all I have come to some conclusions, right or wrong this is what I figure, and the reason I asked the questions in the post.

It seems to me that :

The more you size a case down in dimension the more likely there is to be run out.

The sizing of the neck seems to create runout far worse than the body since the body is well supported.

The use of two dies like a neck die and a body die isn't conducive to minimizing run out.

The more a bush floats the more run out is likely to be produced for a given amount of sizing.

The more room for movement within a neck die like a Wilson that the case has to move around the more runout that will be produced.

A bushes tight entry (excuse me) into them creates runout far worse than the more tapered lead in that the shoulder area in a fixed die effectively creates. The easier transition the neck has into the sizing area the better and a bush hasn't got much transition area only a small radius. You can lessen the run out with bushes by reducing the sizing reduction even to the point of sizing the neck in several steps so each step doesn't create much runout.

I believe the ideal is a full length die made in one piece that sizes the case just the right amount from a chamber that doesn't allow much expansion. The small reduction in neck diameter doesn't promote runout and the case being held firmly by the rest of the die will help hold everything in alignment better than a neck die that has some wiggle room. I tested out a LEE full length die with the expander removed sizing the long skinny case in one hit, it produced pretty well perfect case with just a wiggle on the concentricty gauge dial.

As I said, those are just my observations from messing around making wildcat cases etc .......... Input appreciated.

and the following (partial) reply:

quote:

Originally posted by jackie schmidt:

With many chamber bushing dies, the case neck is already in contact with the bushing before the case body is fully supported. And out of squarness in the bushing, or any clearance, will tend to induce runnout. Just take a good look at cases that come out of many dies.
I am not a big fan of bushing dies, simply too many variables. While it does lock you into a set neck tension, a truly straight one piece die will produce straight cases. Since I tune with the charge, and a tuner, not being able to change neck tension is of no concern to me..........jackie

And then onto your question:

quote:

Originally posted by McFox:
If I reduce the neck's inner diameter far enough for the bullet to take over the part of the expander ball, I should get the same result as with the employment of an expander, but without the negative result of runout by stretching.

I think it "risky" business to let the bullet do the job of an expander - at least using a die with an internal neck diameter set up for expander use. Consider how a standard die works: first the case neck is squeezed down way beyond what is necessary to hold the bullet. Then the expander is wrestled through the case neck to obtain the final neck diamter. This is a very robust process, but not exactly refined. If you were to let a bullet do the job of the expander (on an undersize neck), you run the risk of damaging the bullet at the heel. That is the absolutely worst place you can damage it (compared to the tip, say) for accuracy. It is OK to seat a bullet in a case sized without an expander, but there is a limit to how small the case neck diameter can have been left by the sizing operation and still allow you to get away without a damaged bullet.

In any event, what works for me may not work for you. So if you think this might be a good idea, try it. Reloading is all about experimentation and finding processes that work for you.

- mike

Thanks, Mike.

I fully appreciate your comments on damaged bullet bases. In fact I forgot to mention that I am using bushing dies. Hence, my neck diameters are far from being over-resized and bullets will enter them readily, without being damaged.

I am sizing the necks down just far enough so that an expander would not be workless if it was used.

Great thread with an impressive amount of wisdom.

Thank you, gentlemen.

In reading it, I'm reminded how large an advantage it is to have a custom reamed chamber.

My reasoning is... that the less the case neck expands, the less the bushing has to work the neck.

Which seems to me would minimize runout.

flaco