Too Much Run Out!

[TikkaShooters]

When I full length size my Norma 270WSM brass, my run out is 1 thousandth of an inch.

When I neck size the brass after fire-forming, my run out jumps to 9 thousandths of an inch!

What is going on???

My f/l dies are RCBS and my neck die is Redding.

Thank you in advance for sharing your wisdom!

 

[Broz]

Your neck die could be set too deep try backing it off 1/4 or 1/2 turn.

Another problem could be the die is oversizing the neck too much and the expznder ball s coming up so hard it is pulling the necks off center.

Jeff

 

[TikkaShooters]

Thanks Jeff!

I will definitely try your first suggestion.

What is the solution for your second one?

 

[Broz]

Thanks Jeff!

I will definitely try your first suggestion.

What is the solution for your second one?

Well, leaving the expander ball loose to float can help as it will self center. This can be done by placing a small o ring under the lock nut and only finger tighten. Also raise the ball up as far as possible. That will require a seperate decapint step. Make sure an adequate amount of lube is used and a little on the insides of te necks can help. Then make sure to clean off the lube.

The bast way I hav found that cured it all for me was to sell all my dies and buy redding bushing dies. Not cheap but I now have very true ammo.

Jeff

 

[TikkaShooters]

I see bushing dies in my future!

Thank you for sharing your experience and knowledge!