Experiences with accuracy improvement after reducing runout with dies?

[slm9s]

Just curious about people experiences. I have a rifle that I was getting 1/2 moa 3 and 5 shot groups out of, but the RCBS plain-jane dies I had on hand and was using were only giving .003 or worse on my concentricity gauge. I have "better" dies on the way.

Can you give me your experiences in improving runout in your handloads and how that impacted your group size? I know its all relative - just curious what others' experiences have been.

 

[LawrenceHanson]

It’s been my experience that the practical effects of loaded runout, when actually measured on the target, are often over-rated. In my opinion loaded runout is relatively insignificant compared to several other factors that determine how well we can shoot.
The way I see it there are two separate issues involved with this topic. The first is whether or not loaded runout makes any measurable difference in your groups. And second is how to go about minimizing loaded runout.
I am sure there are a few guys who have the skills and fine-tuned equipment that can actually detect a difference in loaded runout on the target, but I’m not one of them. In my case the wind, mirage, gun handling technique, bench set up, equipment tune, and load tune cause minute details like loaded runout to simply become lost in the noise. I have taken loaded runout seriously for many years and have segregated my ammunition based on loaded runout and tracked the on-target results. Periodic review of my targets over time has shown no obvious trends in accuracy based on loaded runout. And that’s from all of my rifles including factory hunting rifles, varmint rifles, and benchrest rifles.
However, I do feel that for the precision shooter, measuring loaded runout does have some benefits. It can be useful in that it helps you determine the quality of your reloading equipment and allows you to identify deficiencies in individual tools or processes and correct them. This provides you with peace of mind that you have done all you can to produce straight rounds. But be prepared to spend some time and money making that happen. There can be many variables associated with consistently loading straight ammunition and figuring it out could take quite a bit of trial and error.
In some cases, my “plain Jane” dies produced less runout than the more expensive bushing dies.

 

[Dusty Stevens]

Everything helps but usually case runout is not your group size limiting factor

 

[DuaneinND]

I agree with what other posts say. If you have ammo that is at .003 and your best groups are at 1/2moa, you have reached the best groups the rifle/optics, rest/bag, load/bullet, seating depth, or the shooter are capable. Your issue now is to figure out where the weak link exists. What is the run out of a fired case?

 

[watercam]

Also remember that .003" total run-out means an actual 'out of alignment' of .0015" relative to the position of the bullet to the bore. If run-out was over .005" or somesuch, might be a different story.

 

[noload]

I did a load test on New brass and documented run out of .007" on a certain load. That was the worst runout of all the ammo to be tested. That runout load shot excellent compared to the rest that were less runout. Ever since then I do not worry much about a little run out.

 

[chkunz]

First let me say that the answer to your question may depend on the precision level involved. For example, runout may not be important to the M14 shooting the National Match Course at 600 yards but could be in another discipline like F Class or bench rest since those applications require higher levels of precision. I have replied to similar questions on this forum with my experience in collecting data on runout with the M14 at 600 yards. The data did not show a statically significant difference in ammo with near zero runout as compared with ammo with runout of greater than 0.005. So I quit being concerned about runout in this application.

 

[Joe R]

slm9s
Just curious about people experiences. I have a rifle that I was getting 1/2 moa 3 and 5 shot groups out of, but the RCBS plain-jane dies I had on hand and was using were only giving .003 or worse on my concentricity gauge. I have "better" dies on the way.

Can you give me your experiences in improving runout in your handloads and how that impacted your group size? I know its all relative - just curious what others' experiences have been.

slm9s,
before I can respond to your question and provide with irrelevant info I would like to know more about the caliber you are shooting and some of the details of your rifle, ie 30.06 Remington 700 hunting rifle or .284 Win, F-Open, Pierce action, Bartlein, etc...

Regards,

Joe

 

[GerryM]

I don't agree with that theory that .003 runout won't hurt accuracy.

I've found out differently over the years.

I neck turn all of my brass and use a straight line seat die.

My accuracy always improves

 

[Joe R]

GerryM said:

I don't agree with that theory that .003 runout won't hurt accuracy.

I've found out differently over the years.

I neck turn all of my brass and use a straight line seat die.

My accuracy always improves

Gerry,
you may be getting the right results and attributing the credit to the wrong factor. As T-REX and no load posted above I know for a fact that they are correct.

Turning necks is very important. However the objective of turning necks is not to get concentric ammo, that is a fool's errand. I've been there and done that and I have a $400 concentricity gauge to prove it. As a matter of fact if you're getting concentric ammo I am certain that you're not getting consistent SD's (5 or less), ES's (15 fps or less) and precison.

So the real question is: Why do we turn necks? I'll let the guy that taught me (Shootsdots) answer that question. He knows way more than me, I have to look up to see the bottom of his shoes.

Kindest regards,

Joe

 

[tome]

this might be a simple fix. float the die. go to the hardware store and buy a o ring to fit the die threads. put it on and adjust the die and see if you have any improvement.

 

[dkhunt14]

I don't agree with that theory that .003 runout won't hurt accuracy.

I've found out differently over the years.

I neck turn all of my brass and use a straight line seat die.

My accuracy always improves

I believe there is a difference between runout and concentric. Plus neck turning aides in even neck walls which helps in bullet tensions. Matt

 

[Joe R]

dkhunt14 said:
I believe there is a difference between runout and concentric. Plus neck turning aides in even neck walls which helps in bullet tensions. Matt

Matt,
Would you be so kind as to explain the difference.

By the way Matt,
I've been praying for you and your family. I'm glad you're back and I hope whatever health problem, your family was experiencing, is behind you.

Kindest regards,

Joe

 

[DRD1]

Answer for me is MOST of the time. As I have upgraded dies to the Forster/Redding from RCBS/Hornady and tried to isolate runout in groups, the biggest difference has just been consistency with less flyers - that can absolutely drive me nuts. Groups for me on MOST rifles are just more consistent with .001-.003 r/o vs the .005-.007. Avg reduction in the 1/4-1/2 MOA range usually at best. I try to set a number, get to 1/2 MOA and then shut it down. If I get 1 ragged hole, all the better, but lots of other factors. In the long run worth the investment TO ME to upgrade. Still have rifles matched with and set up with less expensive dies with more runout than I would like that shoot lights out. Sometimes becomes a head scratcher.

 

[dkhunt14]

dkhunt14 said:
I believe there is a difference between runout and concentric. Plus neck turning aides in even neck walls which helps in bullet tensions. Matt

Matt,
Would you be so kind as to explain the difference.

By the way Matt,
I've been praying for you and your family. I'm glad you're back and I hope whatever health problem, your family was experiencing, is behind you.

Kindest regards,

Joe

I feel if a bullet is out of center, the throat may not be able to straighten it out. The cartridge may not have enough room to move off center and therefore the bullet will start off-center.
In run out, the bullet will be able to bend the case neck and straighten out some provided it is not terrible. I shot some very bad run out loaded rounds at 1000 and shot very good groups with them. Now I shoot mostly in the lands and believe the throat straightens them out.
As far as the medical issue, it has only just begun. Thanks for the prayers. I really don't know a lot yet. They did the first round of chemo on her. Matt

 

[JarheadAZ]

Please note that in the 1990's, I experienced two bouts with different forms of Lymphoma (apparently a consequence of my USMC service in RVN), It took about 5 years for each bout to be completely recovered.

I found out who my real friends were.

So there is plenty of hope...

Greg

 

[arnie]

RCBS recommends when full length sizing ,leave the expander stem loose and when you have upward pressure on the case from the expander ,then tighten it keeping pressure as you tighten . This has helped to get rid of run out some times . I also find long cases like 30-06 can get a banana shape and they will never go straight into the chamber so discard them .

 

[clowdis]

A round can't have more runout than the chamber that it's put in. If you have a chamber that runout and clearance are no more than .003 then any round that you put into it will have to comform to those same dimensions. In other words, if you have a round with .015 runout and chamber it in your rifle which has a chamber with only .003, the round will have to conform to the chamber.

 

[GerryM]

Those fixtures that measure runout are from a distant past. They even made some that used an anvil to straighten the case necks.
Starting with a concentric chamber and a concentric neck on the cases is one of the keys. I use a custom straight line seater die along with a custom chamber.
One other thing that helps is sizing half to 2/3 of the neck. that allows a better fit in the chamber.
try it it works pretty well .

 

[LawrenceHanson]

A smooth uniform chamfer inside the case mouths has probably done as much to improve loaded runout for me than anything else I’ve tried. Ideally, the bullets should slide into the necks nice and easy and feel consistent every time. I use a 28 degree “VLD” hand-held chamfer tool and then follow up with fine steel wool to remove any chatter or burrs.

I know of a guy who bought five Wilson straight line bullet seaters to use for his 6PPC benchrest rifle. He mixed and matched the various parts from all those bullet seaters until he stumbled across a combination that produced ammunition that satisfied him. This precision reloading stuff can become an obsession. And I wonder what he did with the four substandard dies?