How Best to Fix Excessive Neck Runout

[Phil3]

Fairly new to reloading, but am exasperated with wildy varying and sometimes big runout numbers when resizing new unfired Winchester 223 brass. I am using a Redding FL die with optional floating carbide expander ball, with inside neck lube to minimize tugging on the neck. Press is a Forster Co-Ax. I measured the neck thickness variation on the brass, and it is mostly .0015". Neck runout before resizing averages around .0035". After resizing, this can jump on some case to a whopping .008". Almost all are .004" or worse. Is this just typical of FL dies and expanders? I am willing to go to a Redding FL die with bushings, but understand these do not resize all the way down to the shoulder, a potential issue according to some when used in AR15. ??? Or, is there a method to improve the runout numbers with the regular FL die? Is the FL bushing die the best way to go for an AR? I may use the die for a factory 223 bolt gun as well, so hopefully it could work for that too.

Thanks.

- Phil

 

[ChrisGarrett]

Re: How Best to Fix Excessive Neck Runout

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Phil3</div><div class="ubbcode-body">Fairly new to reloading, but am exasperated with wildy varying and sometimes big runout numbers when resizing new unfired Winchester 223 brass. I am using a Redding FL die with optional floating carbide expander ball, with inside neck lube to minimize tugging on the neck. Press is a Forster Co-Ax. I measured the neck thickness variation on the brass, and it is mostly .0015". Neck runout before resizing averages around .0035". After resizing, this can jump on some case to a whopping .008". Almost all are .004" or worse. Is this just typical of FL dies and expanders? I am willing to go to a Redding FL die with bushings, but understand these do not resize all the way down to the shoulder, a potential issue according to some when used in AR15. ??? Or, is there a method to improve the runout numbers with the regular FL die? Is the FL bushing die the best way to go for an AR? I may use the die for a factory 223 bolt gun as well, so hopefully it could work for that too.

Thanks.

- Phil </div></div>

A Bersin concentricity gage/fixer in small rifle (223/308 family) should work out well for you.

223 brass should have neck wall thicknesses of .011"-.0125".

Chris

 

[427Cobra]

Re: How Best to Fix Excessive Neck Runout

Go fire form them and report back

 

[SPAK]

Re: How Best to Fix Excessive Neck Runout

Try taking the expander ball out of the FL sizing die and use a bushing die or even a lee collet die to neck size. Expander balls can really tweak a neck out of alignment.

And I agree with the others, your runout should improve after the first firing.

 

[steve123]

Re: How Best to Fix Excessive Neck Runout

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Phil3</div><div class="ubbcode-body">Fairly new to reloading, but am exasperated with wildy varying and sometimes big runout numbers when resizing new unfired Winchester 223 brass. I am using a Redding FL die with optional floating carbide expander ball, with inside neck lube to minimize tugging on the neck. Press is a Forster Co-Ax. I measured the neck thickness variation on the brass, and it is mostly .0015". Neck runout before resizing averages around .0035". After resizing, this can jump on some case to a whopping .008". Almost all are .004" or worse. Is this just typical of FL dies and expanders? I am willing to go to a Redding FL die with bushings, but understand these do not resize all the way down to the shoulder, a potential issue according to some when used in AR15. ??? Or, is there a method to improve the runout numbers with the regular FL die? Is the FL bushing die the best way to go for an AR? I may use the die for a factory 223 bolt gun as well, so hopefully it could work for that too.

Thanks.

- Phil </div></div>

Later on after you've fired your brass you can inside neck ream if you really want to reduce runout to minimum.I've recently done this to some brass that was fired a half dozen times.The runout on many of the cases is around .001 now vs .003-.005 previously.

 

[Fuzzball]

Re: How Best to Fix Excessive Neck Runout

" using a Redding FL die with optional floating carbide expander ball, with inside neck lube to minimize tugging on the neck. Press is a Forster Co-Ax."

Well, you have all the gear that conventional wisdom says will make the "best" ammo. Maybe conventional wisdom is wrong...again? (Only trying to point out that equipment really doesn't make as much difference as some seem to think.)

It's true that you can't do much with unfired cases, you are fighting whatever error the manufactoring process produced.


"..runout before resizing averages around .0035". After resizing, this can jump on some case to a whopping .008". Almost all are .004" or worse."

Sizing should not increase neck runout; it frequently does. Causes vary but it's clear it comes from some part of the sizing and that means something about the die. Are you testing cases that are ONLY sized, or those that have also been expanded? Try measuring runout both ways to indentify where the degregadation occurs. Likely comes from the expanding step.


"Is this just typical of FL dies and expanders?"

Pretty much. The floating carbide expander button really decreases the resistance to withdrawing the cases (adding lube is overkill). Sadly, any small ball expander frequently adds to neck runout, longer expanders with more case contact tend to bend necks a bit less than any ball, round or eliptical.



"I am willing to go to a Redding FL die with bushings,"

That may or may not help with runout. IF you have a tight chamber so the necks only need to be sized down a little it can work fine. But, if the necks need to be sized down more than perhaps 4-5 thou the bushing itself will react to the thin/weak side of the neck.


".. understand these do not resize all the way down to the shoulder, a potential issue according to some when used in AR15."

Weelll, there is no point in neck sizing below the point of bullet-to-neck contact. So far as an AR15 goes, if the unsized neck portion is no bigger than it was when original fired it shouldn't be a problem. ??



"..is there a method to improve the runout numbers with the regular FL die?"

If it comes from the die itself, no, it would have to be replaced but that's very unlikely. If it comes from the expander, yes - quit using it.

I had good luck with Lyman "M" expanders for years before Lee's Collet Neck Sizers were available so you may try that. But, the ideal combo seems to be a body die and a Lee neck die.


"Is the FL bushing die the best way to go for an AR?"

Anyone telling you a single tool or technique is "best" for anything would probably lie to you about other things too. The ONLY way to establish something like that is to try it yourself.

For a bushing die to do it's best work the necks need to be turned to a consistant thickness. Otherwise the nice straight outsides will simply push any thickness or angular variation to the inside. (That's why dies are made with expanders in the first place, they at least produce a fairly consistant inside neck diameter!)


"I may use the die for a factory 223 bolt gun as well, so hopefully it could work for that too."

Will it work, sure. But doing that sorta negates part of what custom handloading is all about. Perhaps finding the "best" method for both rifles individually would be better?


Bottom line, no sizer or seater die can correct bad case necks. Try whatever you wish and, if the runout is still greater than you can stand, try light neck turning to reduce neck thickness variations. Don't cut too much or you will only make an already loose fit even sloppier. Those stubborn cases that just can't be corrected can be used for fouling shots...or tossed.

 

[Phil3]

Re: How Best to Fix Excessive Neck Runout

VERY helpful. Thank you.

Regarding at what step does the runout take place, my testing makes it very clear it is the carbide expander. If I resize a case without the expander, the runout is typically a maximum of .002", often less than that. Do the same exercise again WITH the expander, and the runout increases substantially. This is quite repeatable.

You said bushing dies may not reduce runout if the neck has to be sized down more than .004" - .005". I do not understand. If you have bushings, why not select a bushing that only necks down the neck a minimal amount? Is not that the purpose of the bushing die?

Another question on the unsized neck portion when using bushing dies. I see your point about no need to size beyond where the bullet is held in the neck. But wonder why people speak with more concern about this fact when talking about semi-autos than bolt guns?

Since it obvious the expander is causing the runout, I would stop using it (as recommended), but of course the neck is far too small. Somehow, the neck needs to be expanded back up. A mandrel could do this. Is that what should be done? I am not familiar with the Lyman "M" expander or Lee Collet dies, but will look into those.

I will try neck turning using a smallish lathe I am rebuilding.

- Phil

 

[SPAK]

Re: How Best to Fix Excessive Neck Runout

You can use an expander mandrel to re expand the necks to the proper diameter and neck tension. This is harder to control unless you have it machined to the exact diameter that you want you necks to be prior to seating.

Or use a body die in conjunction with either a bushing die or the lee collet die.

With bushing dies you must select the correct bushing to size the neck down to the proper diameter for the neck tension you want. Typically you want to select a bushing .001-.002" smaller than your loaded neck diameter. Your necks should be turned to consistant thickness or the runout problem may or may not go away.


If the bushing you select is greater than .005" smaller than your fired OD you might have run out issues. You are correct that typically the less you are sizing the neck the better your results will be.

The other option is to have your FL die honed out in the neck to the correct diameter to size the neck to your specs...

Personally I like the option of using a body die and bushing dies to control neck tension.

 

[chris19210]

Re: How Best to Fix Excessive Neck Runout

I got a new K&M neck turner yesterday and tried it out...before the case necks had around .003-.004 runout and bullet runout of around .006-008 on the rcbs concentricty gauge. After neckturning and resizing the cases/bullet run out measurements were .001-.00225. Can I confirm this helps at the range? Not at the moment but I would certainly hope so...before I could roll the loaded shell on the desk and notice the wobble in the bullet. My AR shoots pretty well so far and it has never seen a turned case. As others say you need to fire them all first...even some lapua brass I had bought had different hardness to it when doing prep work. ***Test were done on a 264 winmag with a berger 140.

 

[Tripwire]

Re: How Best to Fix Excessive Neck Runout

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Phil3</div><div class="ubbcode-body">
Since it obvious the expander is causing the runout, I would stop using it (as recommended), but of course the neck is far too small. Somehow, the neck needs to be expanded back up.

- Phil </div></div>

FWIW..........

Simply buy another FL sizer die and designate it as the "sizing only" die, set it up to size per your chamber requirements, and leave the expander/decap stem out of it (you will also need a decap die to do this efficiently/correctly since you won't be decapping during the sizing process). Size your cases through this "sizing only" die, THEN expand your necks with your other die and the floating carbide ball in a seperate step. With your designated "neck expander die" screw the expander stem down more than usual so that the case body cannot contact the inside of the die. Expand your necks by pushing them UP over the floating expander ball instead of dragging the ball through the neck as a die is "normally" used.

You will see a dramatic improvement in runout by reversing the direction that the necks are expanded. Pulling a ball up through does far more damage to runout than pressing the ball towards the case head. The physics involved dictates that the brass can support the strain of neck expanding better if the expansion is done towards the case head. The action is supported by the case head squarely seated on the shell holder, which is squarely seated on the ram, instead of rocking around on the case rim as is the situation with pulling it through. The shell holder is not a precise fit on the ram, on any press, and anything pulling "up" on it will produce movement, which will produce inconsistancy.

I wouldn't ream any necks under normal circumstances but I'd damn sure turn the outside if they were far enough out of whack. When turning you need only skiff off the high side to make the necessary improvement. Unless they are grossly thick necks you won't even touch the thinner half. I've been known to size virgin cases, expand the necks, then turn them to shave off the thick side. New cases usually give me very good accuracy.

Squaring the dies to the press is pretty important. I do all my reloading single stage and setting up a die every time I change to another rifle is a pain in the ass. To fix that I use Hornady locking rings (just my preference because they seem easier to set up square because they pinch the die instead of having only a set screw mashed into the threads) and made a "wrench" that fits them. This "wrench" fits my inch pound torque wrench and my dies get torqued to 200 inch pounds consistantly every time I change them out. This returns them to exactly the same head spacing every time, and helps return them to where they are square.

I also dedicate a shell holder to a specific rifle. Not all shell holders are created equal and even though they may be the "same", or from the same manufacturer, they may vary slightly in height/dimension, and change headspace or other case dimensions, and possibly affect runnout. IOW, my 243AI has it's own dedicated shell holder despite also loading for an '06, 308 win, and 243 win with the same shell holder requirements, they too all have their own. The more consistancy you can employ the better off your ammo will be.

Another way to help maintain good concentricity through the seating process is using the comp seater dies with the spring loaded sleeve, I use Redding. The sleeve in a comp die adds much to it but I also turn my cases 90 degrees 2 or 3 times while seating in small gentle progressions until fully seated.

Of course squarely trimmed/chamfered case mouths are also important, to start with....

This/these methods routinely produce sub MOA ammo for me with not much invested in gear or grief. Quality dies are a must though, and knowing little tricks to fool the physics is a plus......

 

[Fuzzball]

Re: How Best to Fix Excessive Neck Runout

<span style="font-style: italic">"You said bushing dies may not reduce runout if the neck has to be sized down more than .004" - .005". I do not understand. If you have bushings, why not select a bushing that only necks down the neck a minimal amount? Is not that the purpose of the bushing die?"</span>

Phil, okay, I didn't make that very clear. And, it's important to understand that BUSHING neck sizer are a BR tool and have much less to offer the rest of us.

What comes into play during sizing is the neck diameter of the chamber. A fired case springs back a little after firing, genterally about 1 thou. We need to size the necks down 2 thou smaller than loaded diameter to insure we end up with 1 to 1.25 thou of "bullet tension." Seems the more we need to reduce the fired diameter the more likely the case will 'drift' towards the weaker side during sizing and the neck will be 'bent' that way.

However, IF you only have to reduce the neck a little bit, say 2-3 thou, a bushing die can be great; that's part of why so many custom rifles use tight necked chambers. In fact, that's exactly why bushing dies were invented by BR shooters, their chambers are so small our common necks wouldn't even fit without turning to a smaller and consistant thickness! Without full circumference turning a bushing die loses much of it's benefit.

For those of us loading for SAAMI spec chambers (sloppy) I don't think anyone's bushing dies have as much potential for straight necks as Lee's Collet Neck dies. 'Course that idea is blasphemy to those who live and die by eauipment cost - "you get what you pay for" - rather than performance. In my humble opinion of course!

 

[Lumpy Grits]

Re: How Best to Fix Excessive Neck Runout

Set your expander ball to be just below(1/8")the bushing so the expander ball enters the neck while the neck is still coming out of the bushing.
ALSO, find a case that has little or no neck RO and insert into your sizing die, then TIGHTEN the bushing stud to "pinch" down on the bushing to hold it in place.
Been doing this for my .308 for years and my RO has a TIR of less than .003"
Respectfully,
LG

 

[Queequeg]

Re: How Best to Fix Excessive Neck Runout

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tripwire</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Phil3</div><div class="ubbcode-body">
Since it obvious the expander is causing the runout, I would stop using it (as recommended), but of course the neck is far too small. Somehow, the neck needs to be expanded back up.

- Phil </div></div>

FWIW..........

Simply buy another FL sizer die and designate it as the "sizing only" die, set it up to size per your chamber requirements, and leave the expander/decap stem out of it (you will also need a decap die to do this efficiently/correctly since you won't be decapping during the sizing process). Size your cases through this "sizing only" die, THEN expand your necks with your other die and the floating carbide ball in a seperate step. With your designated "neck expander die" screw the expander stem down more than usual so that the case body cannot contact the inside of the die. Expand your necks by pushing them UP over the floating expander ball instead of dragging the ball through the neck as a die is "normally" used.

You will see a dramatic improvement in runout by reversing the direction that the necks are expanded. Pulling a ball up through does far more damage to runout than pressing the ball towards the case head. The physics involved dictates that the brass can support the strain of neck expanding better if the expansion is done towards the case head. The action is supported by the case head squarely seated on the shell holder, which is squarely seated on the ram, instead of rocking around on the case rim as is the situation with pulling it through. The shell holder is not a precise fit on the ram, on any press, and anything pulling "up" on it will produce movement, which will produce inconsistancy.

I wouldn't ream any necks under normal circumstances but I'd damn sure turn the outside if they were far enough out of whack. When turning you need only skiff off the high side to make the necessary improvement. Unless they are grossly thick necks you won't even touch the thinner half. I've been known to size virgin cases, expand the necks, then turn them to shave off the thick side. New cases usually give me very good accuracy.

Squaring the dies to the press is pretty important. I do all my reloading single stage and setting up a die every time I change to another rifle is a pain in the ass. To fix that I use Hornady locking rings (just my preference because they seem easier to set up square because they pinch the die instead of having only a set screw mashed into the threads) and made a "wrench" that fits them. This "wrench" fits my inch pound torque wrench and my dies get torqued to 200 inch pounds consistantly every time I change them out. This returns them to exactly the same head spacing every time, and helps return them to where they are square.

I also dedicate a shell holder to a specific rifle. Not all shell holders are created equal and even though they may be the "same", or from the same manufacturer, they may vary slightly in height/dimension, and change headspace or other case dimensions, and possibly affect runnout. IOW, my 243AI has it's own dedicated shell holder despite also loading for an '06, 308 win, and 243 win with the same shell holder requirements, they too all have their own. The more consistancy you can employ the better off your ammo will be.

Another way to help maintain good concentricity through the seating process is using the comp seater dies with the spring loaded sleeve, I use Redding. The sleeve in a comp die adds much to it but I also turn my cases 90 degrees 2 or 3 times while seating in small gentle progressions until fully seated.

Of course squarely trimmed/chamfered case mouths are also important, to start with....

This/these methods routinely produce sub MOA ammo for me with not much invested in gear or grief. Quality dies are a must though, and knowing little tricks to fool the physics is a plus...... </div></div>

Great post!

 

[JGilesEastTx]

Re: How Best to Fix Excessive Neck Runout

I stole chris19210s K&M neck turner yesterday and tried it out...before the case necks had around .003-.004 miles of runout and bullet runout of around .006-008 kilometers on the rcbs concentricty gauge. After circlejerking and resizing the cases/bullet run out measurements were .001-.00225. Can I confirm this helps at the range? Not at the moment but I would certainly hope so...before I could roll the loaded shell on the desk and notice the wobble in the bullet. My AR shoots pretty well so far and it has never seen a turned head. As others say you need to fire them all first...even some lapua brass I had bought had different hardness/erectness to it when doing prep work. ***Test were done on a 264 winmag with a berger 140.

 

[6mmFan]

Re: How Best to Fix Excessive Neck Runout

I would not recommend neck turning using a lathe. In my experience the best way is using a Sinclair neck turner with the case mounted on an electric screwdriver. Before turning the necks you should run them onto a mandrel that is .001" larger diameter than the mandrel on the turner. Use some really good lube while you are turning, and feed the case in really slow. Also when you feed it in you should make sure that you cut into the shoulder just slightly. If your rifle doesn't have an extremely tight chamber then you should not try to clean up all the way around most of the necks. Just 70 percent. Also I would polish the inside of the neck with some 0000 steel wool before turning.

 

[Fuzzball]

Re: How Best to Fix Excessive Neck Runout

The best "case holder" for neck turning I've found is chucking them in my 1/2" battery powered VSR drill. It's not large enough to hold mag cases but I rarely turn mag cases anyway.

 

[steve123]

Re: How Best to Fix Excessive Neck Runout

I just got one of those newish cordless compact size 12V Milwaukee drills.Soooo much better than the full size drills for case prep.Very light weight and one lithium battery lasts for a couple hours.

Sinclair has the handiest case holder I've used.I wish I had got the case family specific one instead of the universal using Lee auto prime shell holders.

The Op didn't realize he was going get all this info,aye

 

[JGilesEastTx]

Re: How Best to Fix Excessive Neck Runout

Steve123 gave best advice as well as 6mmfan. dont put cases in a driver and run them 400 rpm use small handheld device and turn slowly

 

[JGilesEastTx]

Re: How Best to Fix Excessive Neck Runout

Bump

 

[Chanonry]

Re: How Best to Fix Excessive Neck Runout

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Phil3</div><div class="ubbcode-body">Fairly new to reloading, but am exasperated with wildy varying and sometimes big runout numbers when resizing new unfired Winchester 223 brass. I am using a Redding FL die with optional floating carbide expander ball, with inside neck lube to minimize tugging on the neck. Press is a Forster Co-Ax. I measured the neck thickness variation on the brass, and it is mostly .0015". Neck runout before resizing averages around .0035". After resizing, this can jump on some case to a whopping .008". Almost all are .004" or worse. Is this just typical of FL dies and expanders? I am willing to go to a Redding FL die with bushings, but understand these do not resize all the way down to the shoulder, a potential issue according to some when used in AR15. ??? Or, is there a method to improve the runout numbers with the regular FL die? Is the FL bushing die the best way to go for an AR? I may use the die for a factory 223 bolt gun as well, so hopefully it could work for that too.

Thanks.

- Phil</div></div>

OK. My penny worth.

Runout on the case is too high. Fire them. Runout should be about 1 thou.

Use a Redding body die with cometition shellholders to just nudge the shoulder a couple of thou back. Runout should be unchanged. Pretty cheap too.

Trim and make sure there is a decent chamfer inside. I the basic Lee hand trimmer and deburring tools. Certainly good enough. Large volumes might be a pain though.

Use a Bushing neck die (Redding and others). Runout should be back to 1 - 2 thou. If it isn't, live with it, junk the brass or anneal. I have also used a Lee Collet die (cheap) which worked well enough but with my particular mounting for my press I found I struggled to get consistent neck tension (ie sometimes I didn't have any - but that is probably my issue rather than the kit)

Use a competition seating die and runout should be around the 1-2 thou. This is where the chamfer comes in. I had runout all over the place, spoke to the guys at Redding put on a big chamfer and my seating problems went away. Wobble dies are just that.

 

[JGilesEastTx]

Re: How Best to Fix Excessive Neck Runout

Bump

 

[MitchAlsup]

Re: How Best to Fix Excessive Neck Runout

I have not used an expander ball in years. I use bushing dies, and mostly I NO size my cases with an occasional trip through the body die as described by Chanonry.

The trick to bushing dies is not to size more than 0.006" in a single step. Since my Remmy has a large throat, I have to size from 0.3445 to 0.339 and then to 0.334 in two steps. I get nice low runout numbers overall with a few poor ones that go in the foulers group.

Secondly, runout less than 0.003 is "not much of an impediment" to accuracy. Maybe at the benchrest level where the difference between a 5-shout group i the zeros (less than 0.099) wins over a 5-shot group in the low 1s (0.1xx) the 0.003 number needs adjustment. But certainly at the 0.3" to 0.5" range it is a fine metric.