Thread: Fixing Run-out

Bloody 6mm Crudmore. After getting a "new to me" press and making sure I was using VLD type seating stems I'm still only getting 25mm groups @100M and I'm thinking its run-out related.

I built a gauge (pic coming) and my reloads still have around 4 thou run-out minimum. I've got a basic Redding seating die, a Hornady and a 6.5x47 Redding competion seaters, none of them deliver the goods . . . . so is it me and a technique issue with the long pointy 110 gn 6mm sierras or what??

A few things. What resizing die are you using? Have you measured the neck run out of a resized case? How much are you resizing down the neck of your case? .002" below bullet diameter is plenty and .001" is usually enough tension for target shooting.

@Tentman you need to stop beating yourself up on this

Start shooting relics like me that you are just delighted to get the shots on the backing board !

It pays off too

A standard Hornady "New Dimension" size die. I just took 3 new Norma 6.5 cases, resized them to 6.0mm. They came out with an average of .04MM (0.0015 ??) runout on the neck. With projectiles seated using the conventional Redding die, the run-out on the projectile was 0.06mm for a Hornady 105, 0.04mm for a Nosler 100 and a whopping 0.14mm (thats 5.5 thou in imperial right??) for the Sierra 110. I'm seating everything a little bit, then turning 180 degrees for the final bit. Its gotta be something I'm doing . . . .

Originally Posted by akaroa1

@Tentman you need to stop beating yourself up on this

Start shooting relics like me that you are just delighted to get the shots on the backing board !

It pays off too

Hahaha, see you when our rabbit holes merge!

Originally Posted by Tentman

Hahaha, see you when our rabbit holes merge!

I spent the afternoon with my head deep in the American long rifles hole
It's a long deep hole
Actually 42" long
But there is light at the end of the tunnel ( barrel ). It's called a flash hole

Originally Posted by Tentman

A standard Hornady "New Dimension" size die. I just took 3 new Norma 6.5 cases, resized them to 6.0mm. They came out with an average of .04MM (0.0015 ??) runout on the neck. With projectiles seated using the conventional Redding die, the run-out on the projectile was 0.06mm for a Hornady 105, 0.04mm for a Nosler 100 and a whopping 0.14mm (thats 5.5 thou in imperial right??) for the Sierra 110. I'm seating everything a little bit, then turning 180 degrees for the final bit. Its gotta be something I'm doing . . . .

Then ditch the Sierra 110. Close to zero run out in a factory chamber doesn't achieve any better accuracy over run out of .002" in my experience.

I made myself a runout gauge once too, batched ammo by runout from good to bad and went and shot groups.
Im not the best shot out there but I couldn't tell any difference from the bad to good runout ones so stopped worrying about it.

How consistent is your seating depth to ogive?

I blame @Kiwi-Hunter - he started calling it "crudmore" and everything has gone downhill from there . . . .

Maybe it just doesnt like that projectile ?
Have you tried a few different seating depths?

It's too easy to blame runout for the so-so accuracy. As has been said, the projectile/load/powder just may not be the right one.

As for reducing runout, the simplest way is probably to use a std FL die with the expander ball removed and then run a neck mandrel through afterwards.

I had trouble with runout using the Hornady New Dimension dies, think it was the expander mandrel from memory causing it. I switched to Redding and not had an issue since.

I know it might be controversial but for concentricity purposes maybe the Lee neck sizer.....

4 Thou runout is pretty good for standard die sets but 5.5 - 6 thou for the sierra's is not so good, they look like quite a pointy bullet so I am betting that the seating steam does not match the bullet.
I have not checked myself as I am not a good enough shooter and my rifle is not up to it, however it has been said that 3 thou (0.076mm) is what is required to get down to 1/2moa providing the rifle and shooter are up to it.
This takes a pretty fancy die and press setup s well as top quality and sorted brass.