Mandrel or expander ball

[Viperdoc]

Have been trying to reload some of my 223 cases, most of which have a ding in the neck. They are all once fired Lapua brass that were FL resized, chamfered, and trimmed prior to first use. With the neck dings, I tried running an oversize mandrel through the necks first and than a full length resize with a Redding type S neck collet die (without the expander ball), but the necks remained with a slight ding.

I then tried running the same dinged cases through the type S die only with the carbide expander ball in place, and the necks ended up much rounder than with the two step method of mandrel and then neck resize. Seems like the mandrel followed by neck resizing did not do as good a job as when using the expander ball.

So, for those that have done the experiment, how much difference does it actually make doing a two step (oversize mandrel followed by FL die and Type S neck collet die without expander ball) versus one step (FL type S die with expander ball in place)? Would like to save a step, seems like the one step did a better job in ironing out neck dings (according to concentricity measurements), but I am afraid about potentially losing accuracy.

Advice?

 

[necchi]

I tried just useing the mandrel in my rcbs neck turning tool vrs. the expander ball in my rcbs FL die set to just bump the shoulder and checked for any changes to accuracy.
The mandrel is .0005 smaller than the ball so I had different neck tension and that's what I was testing for,, the results showed little disernable change. At 200 the change in group size was so small it couldn't really be determined by the tension or the man pulling the trigger.
In your case (oop's) I'd guess getting the dent out would be important IF it's anywhere near contact with the seated bullet. I'd use the ball -n-die combo.
It's interesting your denting the neck, most auto fired cases I see have a ding high on the case near the shoulder. And most of those form out if fired in a bolt gun.

 

[Viperdoc]

I am getting the dents out of my 223 AR that I added a brass deflector. Used it prairie dog shooting and found that it made picking up the brass a lot easier, but all of the necks are uniformly getting dinged. The mandrel did not entirely straighten them out, and the expander ball did a much better job. Although the concentricity of the actual neck was OK, I noticed that it was hard to place the brass onto the gauge, and some cases were very tight. After running the ball through the neck they seemed a lot more consistent. However, I don't want to lose any accuracy by doing this.

 

[necchi]

I think the only reason folks don't want to use the ball, is that it stretches the brass during extration, thus leading to lower case life.
But the 223 case is a tuff little item,,it can take alot of loadings if a guy's not maxing out the laod each time.

The only real way to know about the accuracy is to load both ways and compare ;D