Problem: My finished ammo measures Total Indicted Runout (TIR) of .002" to .007", with most at .005" or worse. Using RCBS Casemaster Gauging Tool.

Cartridge: 270 Win
Cases: New Nosler, very fine quality
Die: RCBS Seating (standard die)
Bullets: Barnes 140 TSX

Anomalies:
-If I screw the die down to contact the ram, it crimps the case mouth, a lot. So, the die is not contacting the ram.
-Using a drop tube I can get the load density down to about 102%, a slight compression. (Short throat, long bullet.)
-Some cartridges are near perfect, at.002" or less. About 80% are worse.

In the past, with other cartridges, I've simply bought a Redding Competition Seating Die when excess TIR popped up, but I'd like to find a cheaper solution. Kindly share your thoughts.

quote:

Originally posted by Brice:
Problem: My finished ammo measures Total Indicted Runout (TIR) of .002" to .007", with most at .005" or worse. Using RCBS Casemaster Gauging Tool.

Cartridge: 270 Win
Cases: New Nosler, very fine quality
Die: RCBS Seating (standard die)
Bullets: Barnes 140 TSX

Anomalies:
-If I screw the die down to contact the ram, it crimps the case mouth, a lot. So, the die is not contacting the ram.
-Using a drop tube I can get the load density down to about 102%, a slight compression. (Short throat, long bullet.)
-Some cartridges are near perfect, at.002" or less. About 80% are worse.
In the past, with other cartridges, I've simply bought a Redding Competition Seating Die when excess TIR popped up, but I'd like to find a cheaper solution. Kindly share your thoughts.

How do they shoot?? If accurate who cares?

First test is, how do they shoot? You are searching for a solution before you know if there is a problem. In hunting rifles, it may not make any difference.
However, if you are just making ammo, try rotating the cartridge 180 degrees and running it into the seating die again.

Brice

Where does the runout appear, after sizing or after seating? Meaning are you checking the necks for runout "before" seating.

Are you neck sizing or full length resizing and are you using bushing dies or standard dies?

You need to find out at what stage of reloading the case the runout starts and correct and eliminate it.

Do you lube inside necks?

Responses:
-Flyers and poor groups occur when TIR = .004" or more.
-No sizing going on. Using new, very good, straight Nosler brass.
-Not lubing case necks.
-Using RCBS standard seating die.
_Tried rotating cases at 1/2 stroke of the lever.

I've now fired nearly all 100 of the new cases. Will partial FL size and see what happens. Stay tuned.

First of all

.005 to .007 TIR at the ogive is very accurate in a loaded round

99% of the people who claim that thier loaded ammo is dead zero or even under .005 TIR are usually not measuring TIR but just making false claims

I have checked run out on thousands of finished rounds.....mine and factory

In years of testing I found no ill effects unless TIR exceeds .010

BTW.....factory TIR and OAL will shock you and not in a good way

With my hunting rifle I found sometimes TIR matters, and sometimes not. As an experiment I gauged some factory ammo, Norma 180 gn Vulkans, 30.06, and had runout anywhere from .001 to .005, and they easily shot 1 inch 3 shot groups at 100 yds. Cartridge OAL was well short of rifling contact.
My own reloads with 180 gn Interbonds only shoot this well after TIR correction with a concentricity tool.
Currently I am shooting Barnes TTSX 180 gn, seated deep with a Redding Competition Seadting Die ( I still rotate 3 times to seat the projectile ) which tends to give TIR of no more than .002 when gauged and have found this one of the most accurate projectiles I have shot. Have also tried the 180 gn TSX and had very good accuracy. I follow other procedures also which I believe contributes to accuracy of my ammo but have not found TIR to always be an overiding factor.

Leaving all else the same...when I quit lubing inside case necks TIR increases.

Some bullets have more drag/friction when seating which can greatly increase TIR...for these...I relube just before seating.

quote:

Henry Pasquet: I apply Imperial dry neck lube to the inside of my case-necks with a bore mop. The K&M arbor with seating force gauge shows the need to do this. If you put a bullet into a clean case, it will be jerky when seating the bullet. You may see 40 units (on the K&M dial) dropping to 20, then slowly increasing pressure. I explained to a friend that not lubing the neck is like overhauling an engine without lubing the cylinders. Smooth entry gives the bullets a smooth release.

The OD of the bullet aligns with the case kneck when seated

If the case is straight the chances the bullet will seat on C/L greatly increase

Lee collet dies are hard to beat

Stop using the RCBS seater; use most anything else. I have found their quality to be spotty.

Get a Wilson "in-line bullet seater"

I converted all my RCBS full length dies to use the Forster high mounted expander and the resized cases have .001 or less neck runout. This is with cases with .001 or less neck thickness variations.

The Forster expander and spindle assembly float under a thick rubber washer. And the neck of the case is still held and centered in the die when the expander enters the case neck. Meaning the expander can not pull your case necks off center when sizing.



Below a RCBS .223/5.56 die equipped with the Forster expander unit and a Lee lockring with its rubber O-ring that allows the die to float and self center in the presses threads.



Meaning start with a case with minimum neck runout and a good seating die and you should end up with minimum bullet runout.

Reloading: Seating Die Runout
Seating Die Induced Runout - A Comparison
by Germán A. Salazar

http://riflemansjournal.blogsp...ting-die-runout.html

The late Jim Hull of the Sierra bullets test lab and world class competitive shooter made the follow humorous statement because he full length resized all of his cases.

"The cartridge should fit the chamber like a rat turd in a violin case"

You have to think about this for a minuet but a full length resized case is supported in the rear by the bolt face. And is centered in the throat by to bullet, and the case body and neck are not touching the chamber walls. Meaning the case body and neck have wiggle room for the bullet to self center in the throat. And the Military considers .003 or less runout match grade ammunition.

Bottom line, as long as you don't buy 100 Lapua cases looking for 20 perfect cases for your bench rest rifle. You are better off with 100 full length resized cases that can't steer you bullets off center with the bore with slight neck runout.

Get a tool that "adjusts" the run out (see Hornady Lock-N-Load Ammo Concentricity Gage).
Find a round with minimum run out and use it for setting up the seating stem (adjust seating stem with round in shell plate and ram raised so die is "adjusted" to the round) and be sure the seating stem fits the bullet ogive very well.
Are you using neck-turned cases with "perfectly" concentric necks?
Finally, in most cases, it really doesn't matter unless you are in the upper levels of competition benchrest or long-range shooting.

Most ignore the root cause.....the shell holder

"...rat turd in a violin case", eh? Funny, I never thought of it quite that way.

Thanks to all for the thoughtful, informed and useful comments. In this case, a new M70 ASSEMBLED IN PORTUGAL, accuracy is OK but not as expected. For some rifles the runout seems to make a important difference. (Varmint and long range hunting rifles, for example.) I do measure it using a RCBS Casemaster tool. With Redding Comp Seating dies runout is usually .003 or less.

Shellholder at fault? Could it be tilting the case out of alignment?

Afain, thanks.
Brice

Shellholders are designed to be loose but next time you size brass note the location of the case head in your shell holder

In my observations it's not ever as deep as everyone shoves the brass in

This is ok as the size die pushes the case over

The seater die does not do this

But I will add

unless it is fire formed/kneck sized only.....not partial re-sized

Your case is sitting in the bottom of the chamber.....loose as a goose

Bullet runout doesn't mean much it the case isn't centered in the chamber to start with

Oh yeah......the fireing pin drives the case forward into the shoulder hence centering it all up

OK it does......I don't loose any sleep over it

Here's the latest report. After firing nearly all 100 of the new Nosler brass I partial FL sized it using a RCBS die and a Redding Competition shell holder (+.002"). Used Imperial lube on outside and inside.

I loaded 20 rounds of 140 TSX's and 56.0 gr IMR4831, seated off .010". TIR measured .003" to .008". The four groups measured 1.5" to 4". I called all shots. The 4" group was not operator error.

I also loaded a bunch of 130 gr Sierra boat tails for practice. I did no pre-testing, just selected a load of 52 gr of W760 because I have a lot of it. These shot better, 2" groups with no fliers.

I must return the rifle to its owner today, but hope to work on it next season. At 100-150 yards it will kill all the venison he can eat. I will try some of the suggestions, including modifying the seating die. I will also try some other bullets, probably beginning with Accubonds.

Again, thank you all for your help.
Brice

Seating depth will give a far greater return then runout

Close to the lands is a good place to start but most of my "end" testing are off the lands .040 through .120

A ladder test will tell volumes

There is something else (bad) going on if you are getting four inch groups; that ain't caused by runout.

Using RCBS Casemaster Gauging Tool.

I believe you are measuring circular run out. So you are picking up any variation in neck wall thickness. Also if you have a burr on the corner break of the case you are picking that up as well. Make sure your case neck only is riding in the V of the locator it rests on. Your dial indicator is accurate to +/- one increment.
Therefore your true run out may be better than you think.

Based on my experience with TSX...I would back way off of the lands with seating depth. Load some 2 shot sets starting at .070 off in .010 increments down to .020 off.

They like to jump in many of my rifles.

PS:

If you have some H4350...might give it a whirl as Barnes list it as most accurate with that bullet.