All of the responses you have received thus far will help you chase down and eliminate the majority of our runout problems.
One other process that can't be excluded is neck turning. Depending on what type of tool you are using to measure your runout, the variations in the thickness of the neck may well be showing up as runout on your guage.
I try to get my brass in fairly large batches. After following most of the suggestions you have already received, ie, form firing, trim to length, chamfering, etc., I turn the necks of all brass to the same dimension. Brass that appears to require extreme metal removal or none at all are moved to a separate pile for disposal. (Give them away to less picky person!)
Just about without exception, the trimmer will shave a small amount of brass from the necks of cases in odd and unpredictable patterns. Basically, if you have prepped your brass properly, it is shaving off the thick spots.
The brass cases will now, for the most part, have fairly similar and consistent thickness and tension.
Make sure the case necks are clean and smooth prior to using a good sleeve type die to seat your bullets. I chuck up a appropriate size barrel brush in my cordless drill. I have some powdered mica that I put on the brush and give the neck a little cleaning just prior to loading.
Ok I just got back from the bench. I loaded up 6 cartridges and rotated them as I seated the bullets. Here are the results:
Kind of a mixed bag. The measurements were taken on the bullet just slightly past the case mouth.
If I purchase the Lee collet neck die would also need to periodically full size the brass? I apologize in advance for my ignorance on this but the RCBS standard dies are all I have experience with. With winter coming on its a good time to expand my horizons.
Thanks again. Mike
You also have to change your case prep. and sizing operation so the case necks come out straighter . You may have to buy better brass like Lapua . I load for 30-06 all the time and I don't see .009 runout .
The whole process has to be straight not just the bullet seating. If the case necks vary greatly in thickness from one side to the other then you will always see that runout . If the brass is poor quality then skim neck turning and a Lee collet die will help . Having too high or too low neck tension can also affect straight bullet seating . 30-06 has a good long neck so it should support the bullet well in most cases . Variations in neck wall hardness will also cause the bullet to seat crooked especially if neck wall thickness varies greatly .
You must start at the start . Anneal all the case necks , move to a better neck sizer die and bullet seater . Starting with a new batch of good quality brass would also help no end .
I checked the level on my reloading bench and the press. I added a wedge here and there to make sure everything was as level as I could get it. I also think that I need to pay more attention to how I place the case in the press. With me flat based bullets I may not be holding them straight on top of the case mouth as it enters the seater die. In the long run Lapua brass is probably more cost effective anyways. Mike
That is the reasoning behind the seat a little and turn method , because you can't hold it straight to start with.
If you are using old fashioned neck sizer dies with draw through expander balls then it is difficult to get good consistant straight necks especially if the necks are varying in radial hardness and radial thickness .
If you full lenght size at anytime with these old dies you go back to square one with a poor fitting case that needs fire forming .
My advice is buy one only Lee collet die , one Redding comp seater , one Redding body die . If you are loading for a bolt gun . Make a washer that fits neatly over the case body and lays on the top of the shell holder to reduce the length that teh collet die sizes . This gets the collet away from the shoulder junction and produces a slight second shoulder that is never sized because a body die does not touch the neck . This keeps the case better aligned all the time.
I can post this because I wrote it .
Using The Lee collet Die
It does not size like that , it squeezes in on a central mandrel. The only way you can reduce the length of neck area sized is by placing a machined washer over the case onto the shell holder. The thickness of the washer is the length of reduction.
Using The Lee Collet Die.
I started using Lee collet dies when they first came on the market and have found that they are very good for the purposes for which they were designed .
I have found that there is a lack of understanding of how to use the die properly and as a result people fail to see the advantages that the die can deliver over standard neck sizing dies.
This is not the fault of the product , it is just a lack of understanding of how the die works and what it will feel like when you operate the press correctly.
Standard dies use a neck expanding ball on the decapping rod and size by extruding the neck through a hole and then drag the expander ball back through the inside neck.
The collet die achieves neck sizing by using a split collet to squeeze the outside of the case neck onto a central mandrel which has the decapping pin in itís base .
One advantage is that there is no stretching or drawing action on the brass.
The inside neck diameter is controlled by the diameter of the mandrel and to some extent by the amount of adjustment of the die and the pressure applied to the press .
This results in less misalignment than can occur in standard dies because of any uneven neck wall thickness in the cases .
Cases will last longer in the neck area and require less trimming. If cases have very uneven neck wall thickness then this can cause problems for the collet die they definitely work smoother and more accurately with neck turned cases but it is not essential.
When you first receive the die unscrew the top cap and pull it apart check that everything is there also that the splits in the collet have nothing stuck in them then inspect the tapered surface on the top end of the collet and the internal taper of the insert to make sure there are no metal burs that might cause it to jamb.
Next get some good quality high pressure grease and put a smear onto the tapered surface of the collet .
Put it back together and screw it into the press just a few threads for now . The best type of press for this die is a press of moderate compound leverage that travels over centre .
Over centre means that when the ram reaches its full travel up it will stop and come back down a tiny amount even though the movement on the handle is continued through to the stop .
eg. is an RCBS Rockchucker.
This arrangement gives the best feel for a collet die sizing operation.
Place the shell holder in the ram and bring the ram up to full height then screw the die down until the collet skirt just touches on the shell holder , then lower the ram .
Take a case to be sized that has a clean neck inside and out and the mouth chamfered and place it in the shell holder.
Raise the ram gently feeling for resistance if none , lower the ram.
Screw the die down a bit at a time .
If you get lock up ( ram stops before going over centre) before the correct position is found then back it off and make sure the collet is loose and not jammed up in the die before continuing then raise the ram feeling for any resistance , keep repeating this until you feel the press handle resist against the case neck just at the top of the stroke as the press goes over centre and the handle kinder locks in place .
This takes much less force than a standard die and most people donít believe any sizing has taken place .
Take the case out and try a projectile of the correct caliber to see how much sizing has taken place.
If itís still too loose adjust the die down one eighth of a turn lock it finger tight only and try again .
Once the die is near the correct sizing position it takes very little movement of the die to achieve changes in neck seating tension .
This is where most people come undone , they move the die up and down too much and it either locks up or doesnít size at all .
It will still size a case locking it up but you have no control over how much pressure is applied and some people lean on the press handle to the point of damaging the die. A press like the RCBS Rockchucker , that goes over centre each time gives you a definite stopping point for the ram and the pressure that you apply .
There is a small sweet spot for correct collet die adjustment and you must find it , once found , how sweet it is ! Advantages : With a press that travels over centre it is possible to adjust the neck seating tension within a very limited zone. No lubricant is normally required on the case necks during sizing .
If you still cant get enough neck tension to hold the bullet properly for a particular purpose then you will have to polish down the mandrel.
Be careful polishing the mandrel down and only do it a bit at a time as a few thou can be removed pretty quickly if you overdo it.
You can't get extra neck tension by just applying more force. The amount of adjustment around the sweet spot is very limited and almost not noticeable without carrying out tests.
For example , to go from a .001 neck tension to a .002 or .003 neck tension you would be talking about polishing down the mandrel.
There are some other advantages but I will leave you the pleasure of discovering them .
One disadvantage that I have found with the collet die is that it needs good vertical alignment of the case as it enters the die or case damage may result so go slowly.
Also some cases with a very thick internal base can cause problems with the mandrel coming in contact with the internal base before the sizing stroke is finished.
If pressure is continued the mandrel can push up against the top cap and cause damage . If you are getting lock up and cant get the right sizing sweet spot, then check that the mandrel is not too long for the case you can place a washer over the case and onto the shell holder and size down on that.
It will reduce the length of neck sized and give the mandrel more clearance. If it sizes Ok after adding the washer then the mandrel could be hitting the base.
This is not a usually problem once you learn how to use them .
The harder the brass is the more spring back it will have so very hard brass will exhibit less sizing than soft brass because it will spring away from the mandrel more. If this is happening to excess then use new cases or anneal the necks.
Freshly annealed brass can drag on the mandrel a bit in certain cases because it will spring back less and result in a tighter size diameter.
I have experienced it. I always use some dry lube on the inside and outside if I get any dragging effect . Normally you donít need lube.
I make up a special batch 1/3 Fine Molly powder. 1/3 Pure graphite. 1/3 Aluminiumised lock graphite. Rub your fingers around the neck and It sticks very well to the necks by just dipping it in and out and tapping it to clear the inside neck . After a few cases it coats up the mandrel .
Other dry lubricants would work also.
Use the same process for normal neck sizing also.
Written by John Valentine 12 / 11 / 01 c .
The Redding (reg.) Body die has a standard 7/8 x14 mounting thread and differs from standard Full length sizing dies by the amount of the case that it sizes and the fact that it has no decapping rod . It is designed to only size from the junction of the case neck and shoulder to near the base of the case .
Neck sizing and decapping is achieved in a separate die.
The separation of the two sizing operations and the fact that you never perform a full length sizing again means that the fire formed fit of the cases in the chamber is preserved to a greater degree and the neck area is not disturbed because the cases are getting a bit tight and need sizing .
Work hardening of the brass is reduced especially in the neck area which is good for accuracy, changes in neck tension over successive reloads is reduced also.
Case life is increased also in the milder loads.
Using the body die is similar to a standard full length die but it is much easier to adjust. There is no neck sizing resistance to compress or stretch the case and upset head space and no decapping rod to adjust.
As a result you can push the case to be sized, the minimum distance that you require to achieve a nice fit back in the chamber .
Cases that are excessively tight can be pushed further into the die to just bump the shoulder back enough to allow easy chambering .
A good fit of case to chamber in a bolt action rifle that preserves accuracy is achieved when you can just feel slight resistance as you close the bolt but the bolt does close completely to a full lockup position.
Also the effort required to size with a Body die is far less than the effort required to use a standard Full Length sizing die .
The same precautions that you would take with a full length die to avoid excessive head space apply equally to body dies.
Never ever push a dirty or unlubricated case into a sizing die as you may never get it out easily.
Use a very thin coating of a good quality sizing lubricant such as RCBS (reg.) case lube before sizing a case.
The Body die works hand in hand with partial neck sizing where you size only a portion of the length of the case neck .
Bushing dies are very good for partial neck sizing as you can stop any place you like as long as you have enough neck length sized and neck tension to hold the projectile concentric and secure for the purpose for which the ammunition will be used , donít overdo this partial neck sizing, as concentricity is very important and if the grip on the bullet is too short the seater die may have trouble seating straight and just working the ammunition through the action can ruin the concentricity and therefore the accuracy .
As a general rule for non bench rest reloading a minimum of two thirds of any case neck should be sized to hold the projectile.
Once you have settled on a certain length of neck sizing you donít want to ruin it every time you use a standard full length sizing die.
It`s important that reloaders understand the difference between Body sizing dies and standard Full length sizing dies.
The Body die does not touch or size any part of the neck of a cartridge case.
Once you understand the difference the benefits become more obvious.
Reddingís description of the die on their website is slightly misleading as to it's true function , " Body dies are designed to full length resize the case body and bump the shoulder position for proper chambering without disturbing the case neck ". Copyright Redding.
This should read, Body dies are designed to resize from the junction of the neck and shoulder to near the base, and will bump the shoulder position for proper chambering if required, without sizing any part of the case neck.
Neck Turning for a Standard Chamber
I have read many times the statement that neck turning is a waste of time for standard factory chambers.
Well it depends on how you do it .
First you must study the article on neck turning and learn how to turn an accurate case neck.
When you have mastered that you can apply the sizing system outlined below.
There is no denying that turning a case neck for a factory chamber will increase the clearance between the case neck and the wall of the chamber, but you can retrieve this clearance for a section of the neck to a tighter fit than before turning .
With partial neck sizing and body die sizing .
The idea is that you leave a portion of the neck , about one third of the length from the shoulder , unsized at all times.
To achieve this a bushing type neck sizing die or a Lee Collet neck sizing die is used to size the neck only . To shorten the length of sizing in a Lee collet die place a machined washer of correct thickness over the case and between the collet skirt and the shell holder .
This section of neck never gets sized that is why it must be kept short .
If it is too long it can make chambering difficult and there will not be enough sized section to hold the projectile concentric and secure especially in short neck designs like 243 W .
A body die is used to size the remainder of the case when necessary and it doesnít touch any of the neck .
This way you gain some of the benefits of neck turning , without the disadvantage of excessive neck clearance in the chamber.
This is a technique for a bolt action rifle that has already shown to be accurate and you want to improve it .
It is definitely a waste of time employing this idea in a rifle that doesnít shoot well enough to see any small improvement in the groups.
Other methods such as pillar bedding , hand load development , quality projectiles etc, would be more likely to improve the bad shooting rifle .
So work on everything else and when you run out of things to improve , it may be the icing on the cake .
There is no one system of anything that suits every rifle , the secret to performance is experimentation.
Some rifles brake all the rules such as shooting better with Full length sized cases than Fire formed cases.
Things like this can usually be traced back to some inaccuracy in the original manufacture e.g. crooked chambering job.
It's your job to figure out what works and what don't.
This article is designed to help you think about ideas you may not have come across before.
I have been using this system in some of my rifles for many years and find it improves accuracy .
Written by John Valentine 25 / 10 / 07. Copyright.
When I first started reloading .308 Win. and 26 or 30 caliber belted magnum cases, I used standard full length sizing and seating dies. Got bullet runout measured the traditional way (case resting in front of extractor groove and shoulder or neck, bullet in front of the neck or at the bullet tip) and got bullet runout readings up to 7 or 8 thousandths.
Then someone suggested I lap the necks out of those sizing dies to about 2 thousandths smaller than a loaded round's neck diameter. Using the same standard bullet seater, runout measured the same ways got better; up to 5 to 6 thousandths.
And finally, someone else suggested I change the way I chamfered my trimmed case mouths. Use a No. 4 or 5 screw extractor turned clockwise instead of the traditional deburring tool in case mouths. It puts a better angle on it. Then run those trimmed and deburred cases over a bore brush spinning in an electric drill. Using the same standard bullet seater, runout measured the same ways got better; up to 3 thousandths or a tiny bit more. And no more bullet jacked scraped off by that sharp, ragged edge left by traditional case mouth deburring tools. No difference in accuracy between rounds with zero runout compared to those with 3 thousandths.
Tried a few different chamber/micrometer type bullet seaters (Wilson, RCBS, Bonanza and a few others I now forget). No improvement over the standard one as far as runout's concerned. But the RCBS competition chamber type is sure a lot faster.
One thing that helps get bullets in loaded rounds well centered in the chamber throat and leade is having the case neck well centered on rimless bottleneck cases. That's the centering point on such cases when they're fired. If the case neck's not centered on the case shoulder, it won't be well aligned with the bore when it fires. And full length bushing dies do so better than neck only sizing dies. Guess that's why so many winning benchresters have moved away from neck only sizing to full length sizing with bushing dies (no expander ball) over the past several years.
Regarding how a loaded round's case neck fits the chamber neck. . . . . A .243 Win. round will perfectly center its neck and bullet in a .358 Win's chamber and bore when the round fires. Same for a .25-06 round in a .30-06 chamber.