[pearson1662]

My 6.5mm Swedish RCBS dies show just less than .002" runout when measuring the expander decapping rod but .007" when measured at the expander ball. Could this be responsible for the large amount of runout that I'm getting? Can I just replace the expander ball? Will that fix the problem? Can I get a carbide expander ball for it? Thanks, Jay

[Ol` Joe]

How much runout are you finding in your ammo?
where is it being measured, the bullet or case neck?
Try sizeing a case without the expander stem in the die and see if there still is runout present. Take the same unexpanded sized case and run it back through the die with the stem screwed back in just far enough to open the neck back up from the top of the mouth, not expanding it from the case body up, and check runout. This will help you know where the runout is coming from.
Replacing the ball itself likely won`t help, although I`ve heard good things about the carbide ones and yes you can purchase one I believe. I`d suspect the die isn`t square in the press because of slop in the threads and the stem is probably off a bit too. Seat the die with pressure on the bottom by placing a flat shim on the shellholder to square the die or better yet with the die screwed down to touch the ram firmly. Then try tightening the expander stem locknut while it`s also under pressure from the ball being centered in a case neck with the die locked in place. Check runout as you go. Sometimes this works but you`ll need to verify the die squarness everytime you remove the die from the press and replace it. The expander should stay square in relation to the die body as long as you don`t loosen the lockring holding it after being set.
Remember too, the case wall must be uniform in thickness to be runout free. If you have uneven case walls the ball will iron the thicker side out makeing the outer neck oval in shape, and it will appear as runout when you check it although the inside of the mouth will be square with the rest of the case. Good uniform cases, and likely still, neck turning will be needed to remove runout totally.

[pearson1662]

Thanks so much for your feedback! No runout present (.001") measured at the neck when the decapping rod is removed. Does this indicate that the die is square in the press?
but you`ll need to verify the die squarness everytime you remove the die from the press and replace it. How do you verify die squareness?

OK, I've gotten my cases decapped and resized with only .002" or less of runout. When I seat a bullet, I'm still getting .004" or more runout. Also, the case mouths seem to be resized too tight to "readily" accept a bullet. I wonder if this might be causing the bullets to be seated crooked and this is where my runout is coming from.

I pulled the bullets and then reseated them and now I'm getting .002" or less runout. What does that indicate if anything. Thanks, Jay

[Ol` Joe]

Thanks so much for your feedback! No runout present (.001") measured at the neck when the decapping rod is removed. Does this indicate that the die is square in the press?

Yes.

How do you verify die squareness?

Check the first round you size to confirm the die is still setting square.

OK, I've gotten my cases decapped and resized with only .002" or less of runout. When I seat a bullet, I'm still getting .004" or more runout. Also, the case mouths seem to be resized too tight to "readily" accept a bullet. I wonder if this might be causing the bullets to be seated crooked and this is where my runout is coming from.

Now it gets tricky, but you know at least 0.002" of it`s something in the seating operation. I`d also look at the case wall concentricity as the cause of some of the runout, then at the seater its self as a last possiblity (unlikely but possible). Watch your bullet when seating and try not to start the bullet crooked. A tipped bullet will seat slightly off. Try seating the bullet about 1/3 of the way and turning it 180* degrees and seating the rest of the way. Sometimes this can be a big help. The fact you removed a bullet and found less runout when reseating makes me think this could be the problem. The bullet trys to follow the path of least resistance and once you`ve opened the neck a little the bullet is finding it easier to straighten out and seating more concentricly.

Try replacing the expander and running the case back in the die just enough to open the case mouth without resizing the case anymore. Acually pushing the expander 1/2 way in the neck should be enough. Pushing the ball in the sized case should help avoid cocking of the case when the ball comes up through the shoulder area and is unsupported. You only want to loosen the mouth enough to start the bullet straight if you`re haveing trouble with it, kind of like "belling" the mouth for straight wall pistol cases. The use of boatail bullets will ease the problem too.

Personally from my own experiance case wall variation of 0.002" /0.003" isn`t uncommon. This will throw the bullet to one side or the other and can only be fixed by neck turning. Once you get runout down to this point or lower it isn`t really worth trying to get rid of the final couple thousanths. The fix can cause more problems to worry about and I doubt you`ll notice any differance in accuracy with a hunting rifle from it.

Don`t forget the most important part of producing perfect ammo. The proper offerings starting with a young virgin, proper prayers, personal sacrafice, and ending in a toast to the reloading gods with the proper beverages. Failure to properly do any of this voids any possible benfit you gained from all your hard work and can also cause hair lose, impotancy, bindness and others to shy away from you in fear of offending their gods by proxy. :D :D :D :D

If all else as fails get a Lee collet type neck sizer........I find less then .002" run on average when useing one (I`ve five I use on differnt cartridges) and others have reported similar results. You`ll still need to bump the shoulder on occasion with your FL die when they get hard to chamber but its a one or two time in the life of the case thing. They are cheap and they seem to work....

[Clark]

The $70 concentricity gauge could be replaced with a fortune cookie that says, "throw out the expander balls."
To the first order, anyway.

The way that expander balls cause eccentricity is by changing the neck diameter while pulling against an asymmetrical shell holder.

It has been suggested that if one were to remove the expander ball, size the brass, re-install the sizer ball, and then resize then partial size the brass, the expander ball would do it's work on the up stroke when pushing. That would only work if the partial sizing did not include penetration to the point of resizing the neck a second time.

I have never had to use the expander ball to get the bullet started in bottle necked cases. If I did have that problem, I would bell the mouth of the case with the expander ball and not push in to full penetration.

It took me 10 years to get a 1" 5 shot group at 100 yard in 10-20-02.
When I threw out the expander ball, waited for windless days, and cut the chamber concentric to the bore, I went through the 1" barrier and through the 1/2" barrier a year later.

[Bullet]

Ol' Joe Quote -
"If all else as fails get a Lee collet type neck sizer........I find less then .002" run on average when useing one (I`ve five I use on differnt cartridges) and others have reported similar results."

I have a Redding neck sizer could you explain the difference between the Redding and Lee?

[BigBob3006]

pearson 1662,

One thing you may want to try is too have a case fully engaged in the die, then lower the ram about 1/8 th of an inch. Now screw the expander ball up to the point that the ball is touching the inside of the case neck. Without tightening the stem, lower the case slightly so tha a portion of the neck is still in the sizing part of the die and the ball has just entered the neck. Now tighten the die stem. Use a case of which the neck is the same throughout the neck. The expander ball will have been forced too be aligned with the die, and necks will not be pulled out of alignment when being extracted from the die. You will also have to get a universal depriming die to knock out spent primers. This is the method I found that minimizes runout. Good luck.
Bob

[Ol` Joe]

I have a Redding neck sizer could you explain the difference between the Redding and Lee?

Bullet, the Lee die uses a collet that compresses the neck against a mandrel to size it, while the std Redding neck sizer works like a regular die, sizeing down the neck then expanding it back out to the proper diameter. The body area of the Redding has been enlarged to allow it to only size the neck while not touching the shoulder/body of the case. The RCBS, Forster, Hornady, ect neck sizers all work the same as the standard Redding NS die.

Redding also makes a "Bushing neck sizer" that uses different diameter bushings depending on the chamber neck diameter of your rifle to size the case neck to the optimum ID. This die is very popular with the guys useing custom chambers and the necks of their cases must be turned to a given diameter before sizing on order for the die to properly size the neck. They give very repetable neck tension and little runout but are a lot of work in case prep and I doubt most shooters will be able to tell the accuracy gain without a very accurate varmite or benchrest rifle. The bushing die uses no expander ball, relying on the proper bushing to leave the neck ID at the right size to hold the bullet.

Redding bushing die............
http://www.redding-reloading.com/pages/typesbushseatdie.html


The Lee die works well once one figures out the proper set up, they`re touchy to get just right at first, and they eliminate the need for lube also.
Here`s the link to Lee and their die.

http://www.leeprecision.com/cgi/catalog/browse.cgi?1116808930.2999=/html/catalog/dies-collet.html

Both dies will reduce runout, the Redding bushing die has the added advantage of allowing varying the neck tension for optimum bullet pull. The case shoulder in both will, after time, move forward and require "bumping" back with a full lenght sizer or bump die to ease chambering. I wouldn`t use either die for ammo to be used in a lever, semi-auto, or pump action. To be honest I`ve never noticed much difference in my accuracy with loads having runout vs loads with minimal to no runout. Then again I`m not a expert high power or bench shooter.

[Bullet]

Ol' Joe

Thanks for the info.

[pearson1662]

Clark
The $70 concentricity gauge could be replaced with a fortune cookie that says, "throw out the expander balls." :D :D :D :D
I did a google search and found a post in which this issue had been discussed and it was suggested to eliminate the expander ball or polish it down and lap the neck of the die out to .002" less than loaded neck diameter. If I was going to that much trouble (and I might, I enjoy the chase) why not just buy bushing-style full-length dies? What do you know/think about Lee Collet dies? Thanks, Jay

[Clark]

I have not done the experiment of comparing bushing dies, with standard dies, with lapped neck dies.
I AM planning on it in .223.
I have the bushing dies and the standard dies, and Forster will sell lapped out neck dies from the factory.

One problem I have is that I am getting accuracy of .4 moa that has my shooting ability as an out of control variable. I may also get a one piece rifle rest instead of two piece.
Bart Bobbit gets .2 moa with lapped dies, and I don't hold much hope that I can shoot that well, but I am going to keep trying.
link to 1993 posts by Bradshaw and Bobbit (http://groups-beta.google.com/group/rec.guns/browse_frm/thread/7492ba4c79e314ce)

[pearson1662]

I'm not sacrificing any of my young virgins! But I did partake of a small portion of Mr. William's seven year old squeezins, said a prayer and threw out the expander ball! Thanks Clark. Just eliminating the expander ball from contacting the case neck seems to have solved some of the problem. That or the prayers. If anyone is interested, I sanded the expander ball down smaller than the sized case necks and seated the bullets without expanding the case necks. The necks are sized down more than is necessary but the bullets will go in straight. I incorporated Ol' Joe's suggestion and turned the cases 90 degrees twice while seating and now total tunout is .002" or less. This is good enough for all of my guns intentions. I really appreciate the expert help you all have provided. Problem solved! Now I can't blame my groups on anything but me. Wait a second that can't be right. Must be the gun. Stinkin' Swede! :p Jay