Neck Sizing Question

[Jdillon]

For those of you who are neck sizing your brass, is it necessary or recommended to run the expander ball/plug? On new brass, I am outside neck turning the brass after running through a mandrel then neck sizing. Just processed 20 new Norma cases for 300 WSM and the runout for many of the cases exceeded .002" which is not acceptable. When neck sizing (Redding Type S) used a carbide expander ball. Could the neck expander be causing the runout? Didn't check runout before processing cases.

 

[Walkalong]

For those of you who are neck sizing your brass, is it necessary or recommended to run the expander ball/plug?

No, if you are going to that much trouble, do not use a standard expander.

Could the neck expander be causing the runout?

Yes, very likely. Use a bushing type sizer.

Didn't check runout before processing cases.

No way to know if you do not check at every step.

 

[Jdillon]

Thanks for the reply. Use bushing type on some calibers and will need to invest in one for 300 WSM. Use Redding Competition Neck Sizing dies for my Swift and don't have that issue. Checked some of the new Norma brass and runout exceeded .002".

 

[kelbro]

Where are you measuring your runout? On the neck of the brass or the bullet? .002 is a pretty high standard.

 

[Jdillon]

On both. The cases necks after working then the bullets after seating.

 

[Walkalong]

.002 is a pretty high standard.

Depends on the application.

 

[Jdillon]

Its for a hunting rifle (Rem CDL SF) but I guess I'm just a perfectionist and like to get the most out of my rifles. This particular rifle has shot 3 shot groups at 100m that a dime would cover but not after lots of tuning.

 

[ArtP]

It makes a difference whether you're measuring the neck or bullet to come up with .002. Runout at the bullet will be higher than the neck. If your neck was out by .001 and you added another .001 during seating (measured at the bullet), I would call that very, very good.

I've never found any difference in accuracy unless runout is higher than .003-.004 at the bullet. Most factory ammo measures .005-.010 with some as high as .012.

I use a collet die which doesn't appear to add any runout then seat with a Forster BR seater which does add a tiny amount. I also notice after fire-forming, cases with bad runout tend to get much better.

 

[bigedp51]

On standard reloading dies if the die body and expander button are not centered "BEFORE" the lock ring is locked down you "WILL" induce neck run-out due to the die body and expander button pulling the neck off center.

The 1974 Speer reloading manual number nine has a very good section on bench rest accuracy and setting up your reloading dies for minimum neck run-out. "AND" there is a reason why accuracy nuts use bushing dies with floating neck bushings that "DO NOT" induce neck run-out along with high quality in line seating dies.

 

[bigedp51]

Neck run-out part two

"O-Rings on Dies May Reduce Run-Out"
(the o-ring allows the die to "float and be self centering)

http://www.accurateshooter.com/technical-articles/reloading/o-rings-on-dies-may-reduce-run-out/

"How to Load More Concentric Ammo"

http://www.accurateshooter.com/technical-articles/reloading/how-to-load-more-concentric-ammo/

 

[Jdillon]

Thanks for the info and links to articles.

 

[kelbro]

Through LOTS of testing, I have found than most of my dies will produce brass with .001-.003 of neck runout.

The problem with 99% of them has been the expander. Remove the expander and measure for yourself.

Expanders with the carbide balls help in some cases.

Mounting an o-ring between the expander stem and the die helps in some cases.

Mounting o-rings between the die and press helps in some cases (if the lock ring is perpendicular to the centerline of the die).

Floating bushings seem to help in nearly every case.

What seemed to provide the most concentric brass was annealing before any or all of the above.

 

[Walkalong]

Letting the brass center the die works as well. It is covered by Speer.

Starting with quality brass can make all the difference in accuracy. All the prep in the world cannot help some brass. Norma is good, but Lapua is the best if they make it for the caliber you are working with. Only question would be, is it worth it for the gain in a hunting rifle.

 

[Jdillon]

Unfortunately, Lapua does not make brass for the 300 WSM or at least haven't been able to find it. Have a Redding Competition neck sizing die on order and will try it without the expander to see if that helps.

Thanks again for all the good info.

 

[quartermaster]

I would say that if you don't lube the inside of your necks before running the expander through it, you could be adding run out to your cases.

Sometimes there is not too much you can do with factory brass. I have prepped brass for 2 different calibers in the past 2 weeks. All were Norma. I have 3 25-06s and am having a Ackley being made, so I purchased 250 cases. I didn't check the neck run out on all of them, but on most of the ones I did check, it was generally .0015- .002. I did check all the necks for thickness deviation. I found about 140 fo them were .001 or less, 70 of them were between .001 and .0015, and the remainder had more deviation than .0015 up to .002. I really had hope for a bit better uniformity.

My other cal was 30-06. I only had 100 of them. Using the same procedure as I used for the 25-06, I found the neck run out to be about the same, but checking the neck thickness variation, I had 70 with less than .001, 20 between .001 and .0015 and the other 10 were .002 or less. I was much happier with these results. If you wanted to help your situation at this point and wanted to spend the time doing it, neck turning the cases to get uniform neck thickness would help. I won't do it with the 30 cal but probably will for the middle group of the 25s. I have been told that neck thickness variations continue up throughout the case. I guess it makes sense, but will never know.

I have learned over the years that upon fire forming the neck runout will be virtually zippo when checking the oujtside of the neck , hence the importance of checking neck thickness deviation. It is at this point that our jobs are to keep as much of this concentricity as we can. I use bushing dies to neck size and a Coax press in which the die body floats in the press. After taking my time to not stress the cases, by sometimes bushing down the necks in 2 steps and using lube to do so, and carefully seating bullets with a Redding competition dies. I still end up with a couple of cases with more bullet run out than I would like. In general, most will be excellant (never perfect), some will be very good and then there are always a few which may end up having .003 to .004, with an exceptional one here and there worse.

I guess my point is that until you do all the prep and fireform them, you can expect neck and bullet runout no matter what brass you use. I do wish Lapua made a bigger selection of brass, but overall, I'm pretty happy with Norma.

I don't benchrest shoot, but I'll admit that I go a bit crazy and overboard trying to sqeeze out all the accuracy I can out of my rifles. It is fun and a labor of love.

Had to throw in my 2 cents.

 

[ranger335v]

"...neck sizing your brass, is it necessary or recommended to run the expander ball/plug?"

If you don't use an expander before seating the bullet becomes it's own expander and it's held much more loosely than an expander.

There is no point to turning necks thin enough to insure perfect concentricity for use in a SAAMI chamber, you will only be making an already sloppy fit worse.

Carbide expander balls make withdrawal easier, they do nothing for concentricity. Thin or soft places in a neck expand easier and expander balls follow the weakness; no amount of fiddling with expander centering will make that any better.

Get a Lee Collet Neck Die and don't bother with the bushings; the finished necks will be as straight as the individual cases will allow.

 

[quartermaster]

One thing I didn't mention in my last post is that if this brass was Win or Rem, I would discard the ones with the large neck thickness deviation, but the more expensive brass gets separated out and used for foulers, unless the quantity dictates neck turning. Doing that would give me a chance to check out my theory about the difference in thickness running up through the case by checking them after a few firings. I have never done that before, but with the large quanity of the 25s which fall into that category, it would present a good opportunity to do so.

Sometimes I think about when I first started reloading and didn't have the tools to check concentricity or the neck thickness guages, reloading was a lot simpler. I guess we all started like that and expanded our horizons to strive for that extra accuracy. It seems to me to be a science now, I wouldn't want to think about how much money was spent on complete sets of new dies, presses etc, not to mention the 1/2 full bottles of powder and bullets that had to be tried. I never regret doing any of it though. I gain much satisfaction reloading and on occasion some frustration. I think my next project will be to have some custom barrels and sction truing done to reap some of the rewards from my reloading efforts. It will be a slow process and only done when finances allow. If you have never done this before, go th the 6mmbr site and click on barrels. Check out the video which compares factory to custom barrels. It has inspired me. If I could only hit the lottery!

You gotta love it

 

[USSR]

...neck sizing your brass, is it necessary or recommended to run the expander ball/plug?

From Redding:

A decapping pin retainer is also supplied with most Type S - Bushing Dies except 17 and 20 Cal. This enables neck sizing without the use of the size button for those who sort and/or turn case necks for uniformity.

Ditch the expander ball or even remove the decapping pin altogether. Using an expander ball with a bushing die negates the primary benefit of bushing dies: straight necks. I have the Redding Competition neck sizing dies, and I have removed the decapping pin and do all my spent primer removal with a Universal Decapping Die.

Don

 

[quartermaster]

With all due respect, Ranger3325v, I believe it is important to run an expander through the neck on new brass. Carbide with some lube is better than the normal expanders, for sure. If you check neck thickness and come up with the right size bushings to give you the correct neck tension, the bullet will not flop around.

I feel that after fire forming brass, anytime you run the expander through the neck, you are taking an almost perfectly concentric neck and taking the chance of changing it where neither collect dies or bushing dies can put it back to where it was. I have read where guys will take a case with bad bullet runout and try to straighten it buy putting it in a hole of some sort and moving it up and down or sideways. That to me would take the neck tension away or make it very even which I believe would have an adverse effect on bullet release.

As far as neck turning goes, one for sure, does not want to make the necks too thin. If the thickness deviates that much, bite the bullet and chuck the cases. Without some sort of uniformity in neck thickness, bullet release will suffer also, as the neck tension will not be even around the bullet. I do not neck turn very often and when I do, it's only to get the cases so that the deviation is .001 or less with out removing very much material and sacrificing the integrety of the neck. You certainly don't want enough room to drive a truck between your neck and chamber.

I made the decision a while ago to get the bushing dies as opposed to the collet dies. It wasn't an uneducated choice. I read many, many forums and articles pertaining to that suject as well as contacting manufactures of both. I went with the bushing dies, despite the great extra cost, just because my gut feeling told me that was the way to go. I have never used a collet die and don't regret my decision to select the bushing die sets. I do highly recommend the comp seating dies made by the same mfg as my bushing dies. Possibly that influenced my decision. After all having all nice green boxes lined up looks good. Only kidding.

I certainly won't knock the collet dies at all. I know that a lot of reloaders use them very successfully. Which choice is best? I feel that we are all happy with what we have.. After loading thousands of rounds, I love the bushing option and I'm very happy with the results I acheive.

I don't believe you can fairly knock either of them