Help, concentricity problems.

[AJ Peacock]

All,

I've been reloading (clean, deprime, prime, powder seat) for 30 years. All my rifles will shoot sub-MOA.

My problem is that until recently, I just worked up a load, reloaded (sorted brass by weight), weighed each charge and called it good.

Since I ordered a 338AM from Kirby, I decided I needed to be able to measure things like bearing surface length on my bullets (so I got some stoney points gauges), Concentricity (so I bought a Sinclair gauge) etc.

Well, I grabbed my box of Norma 7RM brass (mostly once fired, some still virgin, some loaded) and started checking the concentricity.

WHOA!! measured just in front of the neck, the loaded rounds run from .0015 - .008 runout. The once fired measured on the neck runout .002-005" and the new virgin cases run .002-.004" runout.

I immediately measured some of my .243 winchester rounds same type of resolts, then the 7mm-08 same thing, then some factory Remington 7RM, it measured .002-.006" runout

On the .243, I use Pacific neck size dies, on the 7RM I use Forster Neck die, on the 7mm-08 I use RCBS full length.

I polished the expander button on the 7RM Forster neck die, and resized some of the brass; no real change before-after on case neck runout sometimes .001 better sometime .001 worse.

I'm not setup to measure neck thickness.

Since its pretty much the same on 3 different calibers and the factory ammo, do I have a problem? The runout numbers above are extreme spread on the dial indicator. I read that .002" was an allowable limit for runout with bench guns etc. These are all factory chambers with nothing done to the brass but trim/chamfer flash hole debur.

I'm using the same Rock Chucker single stage press I've been using for 30 years.

I now understand the saying "ignorance is bliss".

Any ideas are appreciated.

Thanks,
Don

 

[royinidaho]

Don,

Be careful and don't fall into the category of a "tinkerer" as Kirby calls people like me.

If you're getting sub-MOA with what you have and that's been good enough why won't it still be good enough?

I tinkered too much and ruined a bunch of 270AM cases by neck turning just a bit to much. Kirby had said to not turn them, but hey what does he know" /ubbthreads/images/graemlins/crazy.gif

My run outs, with the sizing die and seating die Kirby sent with the rifle, are 1 thou around the zero mark at best and maybe 3 thou around the center mark at the worst. What I'm trying to say is that the center line of all cartridges is the same. That must be good /ubbthreads/images/graemlins/confused.gif So I get 2 thou to 3 thou run out.

Having said that, the big girl shoots better than I can shoot it. I'm down to shooting 1 shot groups up to 300 yds and my first and only two shots at 1K were on the same horizontal line and 4" apart.

That was the long answer /ubbthreads/images/graemlins/crazy.gif

Short answer is Don't sweat it? When you get your AM turning necks will be one of the last things on your list of things to do. And you'll most probably never NEED to get that far down on that list.

 

[Buffalobob]

AJ

I would have saved you all that money but loaning you my runout device, neck turners, meplaters, and bearing surface measures, The bearing surface measurers are new and never even opened, just looking at them was enough to make me go crawl under the bed and hide. The runout gauge has so much dust on it that you would have to spend an hour cleaning it up.

Your runouts are just minor league numbers compared to mine.

Here is a tip that might or might not help. I do it and like it but my runouts are still 0.01 to 0.007 at the ogive so it did not help me. -- take the spring clip off that holds the shell holder in place and slide a rubber O ring onto the groove. You will have to move it down to put in a shell holder and roll it up again to hold it in place. This will allow the shell holder to move to "line up" as the cartridge case moves up into the die.

Second tip-- as you seat a bullet only pull the handle down far enough to start the bullet and then ease it up and reach in and rotate the case a quarter or third of a turn and then seat the bullet a little more and once more raise the die up and rotate the case still more and then seat the bullet still more. Do this about three times to get the bullet seated. The theory behind it seems to be that sometimes the bullet starts seating misaligned and by rotating you force it into alignment. I do it but I don't really know if it works. I does give you nimble fingers being as your right hand will try to squish your left hand fingers while they are under the die.

The other thing that causes word wars is the Lee Collet Neck Die versus expensive neck dies. I ordered one yesterday because the proponents say they are idiot proof and will give you good neck numbers. We will see.

I am with Roy. If your new gun stays under 0.5 MOA at three hundred yards with just routine reloading techniques then take a box and chuck all of your expensive mental misery devices into it and put them away.

The people who routinely launch bullets past 1K seem to pretty much agree that a lot of stuff begins to matter a lot at those ranges and I guess if a person is going to try for hits past 1K, a person should begin applying every possible techinque to minimize dispersion.

 

[AJ Peacock]

BuffaloBob,

I use that exact technique when seating bullets, don't know if someone told me to do it that way, or I 'thought it up'. Been doing it for years.

Thanks on the shell holder idea.

"Mental Misery devices" LOL, that was great.


Thanks,
Don

 

[royinidaho]

I lost that shell holder spring years ago and replaced it with nothing.

I set the shell holder in with the opening facing left which gives the case both the X and Y axis for movement and it stays in place when using it. I have no idea if it helps with run out but sure doesn't seem to hurt and it is convenient /ubbthreads/images/graemlins/wink.gif

 

[AJ Peacock]

[ QUOTE ]
Don,

Be careful and don't fall into the category of a "tinkerer" as Kirby calls people like me.

If you're getting sub-MOA with what you have and that's been good enough why won't it still be good enough?

I tinkered too much and ruined a bunch of 270AM cases by neck turning just a bit to much. Kirby had said to not turn them, but hey what does he know" /ubbthreads/images/graemlins/crazy.gif

My run outs, with the sizing die and seating die Kirby sent with the rifle, are 1 thou around the zero mark at best and maybe 3 thou around the center mark at the worst. What I'm trying to say is that the center line of all cartridges is the same. That must be good /ubbthreads/images/graemlins/confused.gif So I get 2 thou to 3 thou run out.

Having said that, the big girl shoots better than I can shoot it. I'm down to shooting 1 shot groups up to 300 yds and my first and only two shots at 1K were on the same horizontal line and 4" apart.

That was the long answer /ubbthreads/images/graemlins/crazy.gif

Short answer is Don't sweat it? When you get your AM turning necks will be one of the last things on your list of things to do. And you'll most probably never NEED to get that far down on that list.

[/ QUOTE ]

Roy,

I'll try not to sweat it, I just don't want something in my control to cause problems with the new rifle. I just want to wring the best I can from it. If I could figure out how to reduce my existing runouts on my existing rifles, then that is cheap education compared to learning those lessons with the new rifle and the expensive components.

Thanks,
Don

 

[Chawlston]

Hello,

It is hard to extract all the accuracy from your rifle where the runouts exceed .003" on your loaded rounds. Shooting sub-moa is good for factory rounds (most can be tuned to shoot better), but when you start constructing ammunition yourself, you will find it very easy to get under the .003" runout if you get rid of the expander ball dies and use the bushing style dies along with cleaning up the necks to where the high spots disappear. It is very simple, but you will have to be able to measure the neck thickness or have someone do it for you.

Finally, you can turn the necks to work with your sizing die without the expander ball. I do it on my 30/338 Lapua and it works great.

James

 

[royinidaho]

I've been thinking of sending Kirby my Wilson 270 Win Case holder and have it opened for the AM then use the Wilson 270 inside neck reamer.

I've used it on my 270 Win for over 30 years and since the Lilja bbl has been installed the groups have run as low and the 1s and hangs around the 4s @ 200 the wind not withstanding.

Also the reamer is used after firing and before sizing which eliminates the expander ball from the eq'n.

Neck turning is a bit of a different as the expander ball goes through the neck first.

But either way, I see no problem getting my AM coyote accurate out to 1100 or maybe a bit more.

 

[Chawlston]

[ QUOTE ]
I've been thinking of sending Kirby my Wilson 270 Win Case holder and have it opened for the AM then use the Wilson 270 inside neck reamer.

I've used it on my 270 Win for over 30 years and since the Lilja bbl has been installed the groups have run as low and the 1s and hangs around the 4s @ 200 the wind not withstanding.

Also the reamer is used after firing and before sizing which eliminates the expander ball from the eq'n.

Neck turning is a bit of a different as the expander ball goes through the neck first.

But either way, I see no problem getting my AM coyote accurate out to 1100 or maybe a bit more.

[/ QUOTE ]

Hopefully this does not hurt any feelings but...........

Neck reaming is a chainsaw approach to a surgical problem. You cannot control the thickness of the cut or the thickness of the neck during neck reaming. Neck reaming still relies on alignment of the cartridge to the cutter for a straight cut. Turning the necks is the absolute most accurate way to get it done and really the only smart way to approach the issue of concentricity..

Several years ago, I thought the same thing about neck reaming. Now, I have some neck reamers for sale if anyone would like some.

Neck reaming is only good for getting the "dreaded doughnut" out of a case neck and not for addressing concentricity issues due to neck thickness irregularities.

James

 

[kraky]

Here's what I paste when people talk about runnout. I've fine tuned my dies via this method for years. People have written me back and said it worked great for them too. It's just a simple way to get the expander ball back as near to the center of the die as possible. Most my FL dies will give me loaded ammo as good as any lee collet die and I've come to believe the neck tension is more consistant with the fl die. Anyhow here's what works for me:

My $.02 worth---ALL dies with expander balls need tuning. Think about it...a piece of typing paper is .003" thick--what are the odds that the expander is not PERFECTLY centered in a die and could pull a case slightly off center??? Pretty good I'd say. Pull the expander stem out of the die (and now is a good time to clean the inside of the die). Run about 5 brass into the die and see if they come out concentric. If they do (and usually they will) you now have to try and get that stem centered on re-assembly. A great way that helps is to put a piece of very concentric brass up into the die to hold the stem in place as you tighten it down. Sometimes this takes 2 people unless you have 3 or 4 hands. AFter reassembly try sizing some brass and check runnout. If not good then do very small turns of the expander stem--probably 1/32 of a turn at a time. Resize some brass and repeat the small turns. At some point I can almost guarantee that you will get GREAT RUNNOUT CONSISTANTLY. (Somehow, someway the expander spindle will hit almost perfect centering in the die body) I have many dies that consistantly make less than .002" runnout after sizing with most of the brass at .001" and less. I own, hornady, redding, forester, rcbs, and lee dies. ALL OF THEM HAVE BEEN TUNED and most make fantastic ammo and all make good ammo!! I have never ever got a set of dies from any factory that made as good of ammo as those that I have done this simple work with.

 

[royinidaho]

No hurt feelings here.

I'm not sensitive to revealing where I've been and where I am, so as to be able to accept sincere recommendations to be able to improve.

 

[Chawlston]

[ QUOTE ]
Here's what I paste when people talk about runnout. I've fine tuned my dies via this method for years. People have written me back and said it worked great for them too. It's just a simple way to get the expander ball back as near to the center of the die as possible. Most my FL dies will give me loaded ammo as good as any lee collet die and I've come to believe the neck tension is more consistant with the fl die. Anyhow here's what works for me:

My $.02 worth---ALL dies with expander balls need tuning. Think about it...a piece of typing paper is .003" thick--what are the odds that the expander is not PERFECTLY centered in a die and could pull a case slightly off center??? Pretty good I'd say. Pull the expander stem out of the die (and now is a good time to clean the inside of the die). Run about 5 brass into the die and see if they come out concentric. If they do (and usually they will) you now have to try and get that stem centered on re-assembly. A great way that helps is to put a piece of very concentric brass up into the die to hold the stem in place as you tighten it down. Sometimes this takes 2 people unless you have 3 or 4 hands. AFter reassembly try sizing some brass and check runnout. If not good then do very small turns of the expander stem--probably 1/32 of a turn at a time. Resize some brass and repeat the small turns. At some point I can almost guarantee that you will get GREAT RUNNOUT CONSISTANTLY. (Somehow, someway the expander spindle will hit almost perfect centering in the die body) I have many dies that consistantly make less than .002" runnout after sizing with most of the brass at .001" and less. I own, hornady, redding, forester, rcbs, and lee dies. ALL OF THEM HAVE BEEN TUNED and most make fantastic ammo and all make good ammo!! I have never ever got a set of dies from any factory that made as good of ammo as those that I have done this simple work with.

[/ QUOTE ]

If you buy the most concentric type die, you won't have to tune it. Expander ball dies do not produce as good ammo as bushing dies unless the expander ball is removed and the necks sized to use the die without the expander ball....

When you are pulling the case out of the die during the sizing process, how do you ensure proper case alignment to compete with the necks being centered when the case is firm in the die for bushing style dies..... Keep in mind we are attempting to get zero bullet runout ammo. Expander ball process is for just loading ammo and dies used without expander balls are for making supremely accurate ammo. Go to a becnhrest match and count the number of expander balls in use. I would venture that you won't find any. At least I have never heard of or seen anyone compete using expander ball dies for competition.

Remember, we are trying to get zero runout ammo.

James

 

[kraky]

I never argued that bushing dies weren't good. The POINT of my post is to let people know they can make really good ammo with the dies that so many people already have sitting on their shelf. I have many sets of conventional dies that make alot of ammo at about .0015" and under.
NOt that I think my factory weatherby and browing Bar (two of my favorite hunting rifles) would know the difference betweeen .001 and .004" runnout. But my fussy 300 wby ultralight did shoot a 1.1" 300 yd group the other day.
Not everyone has an arsenal of match grade hunting rifles or benchrest rifles. If you do then by all means go ahead and feed them with ammo made with bushing dies.
In the meantime alot of good shooting ammo can be made for the rest of us with the dies we have sitting on the shelf right now. AND alot of that ammo will shoot good not because it has .001" runnout or .003" runnout but because through alot of experimenting the reloading has found the exact right powder, bullet, and seating depth combination.

 

[Chawlston]

[ QUOTE ]
I never argued that bushing dies weren't good. The POINT of my post is to let people know they can make really good ammo with the dies that so many people already have sitting on their shelf. I have many sets of conventional dies that make alot of ammo at about .0015" and under.
NOt that I think my factory weatherby and browing Bar (two of my favorite hunting rifles) would know the difference betweeen .001 and .004" runnout. But my fussy 300 wby ultralight did shoot a 1.1" 300 yd group the other day.
Not everyone has an arsenal of match grade hunting rifles or benchrest rifles. If you do then by all means go ahead and feed them with ammo made with bushing dies.
In the meantime alot of good shooting ammo can be made for the rest of us with the dies we have sitting on the shelf right now. AND alot of that ammo will shoot good not because it has .001" runnout or .003" runnout but because through alot of experimenting the reloading has found the exact right powder, bullet, and seating depth combination.

[/ QUOTE ]

You have missed the whole point of the thread. He is only trying to solve the concentricity issue. We are not debating the merits of your or my reloading processes. We are (again) trying to solve the concentricity issue he has with HIS equipment.

He already knows that good ammo can be made with the dies he already has because he has been doing that. ..... He is trying to make great ammo and to solve a concentricity problem and I surmise he would like to do it in the easiest manner possible.... Like I said previously......... You can turn the necks on your brass and use your dies without the expander ball and it works fine. I have done this with great success. You can also tune factory ammo by adjusting seating depth. I do this for my hunting buddies and all of their factory rifles shooting factory ammo way less than 1/2 moa. The point I am making and it has been written in many publications is that the expander ball is a source for many accuracy problems. Using an expander ball creates a two step neck sizing process whereas bushing dies or turned necks to match your FL die will produce far superior results compared to expander buttons. This is a long range hunting website and it is dedicated to equipment and techniques to make this possible.

If you are shooting at 1000 yards and have an moa gun, you are basically aiming a 10.5" circle. If you are shooting a 1/4" moa rifle then you are aiming a little over a 4" circle. It is much easier to to hit the target when the aiming dot is smaller than the target vice the opposite.

Remember, the goal is to putthem into the same hole when testing (ie "groups" not "patterns").

James