How To Modify FL die (open neck area up)

[Clint M]

I want to modify a FL die for a factory 7mm-08 Sako factory rifle. I have read several post stating by enlarging the neck area of the die so it doesn't work the brass so much resulted in a die that produced concentric necks. I picked up a new/old RCBS FL die set which I plan to modify... My question is how to open the die, just how hard is it ? I have a lathe highspeed steel, carbide, ceramic... just thinking it looks like a brake hone would work good if it fit inside the neck area.

I was thinking of a finished die that reduces neck by ~.006" and using the expander ball as the final sizing. Any thoughts or ideas would be appreciated.

Clint

 

[David Sengelaub]

I have done this on several dies for the same reason. I also found the necks to be straighter when the expander is pulled through with less resistance.

The only way I would do it is on a ridged honing machine. A flex hone or a brake hone is going to bell mouth the hole and you won't be happy. Find somebody with a Sunnen pedestal hone, it's a easy job.

 

[Clint M]

Thanks David...... I was afraid of that. I will get someone to hone it out.

 

[bigedp51]

You yourself would have a hard time opening up the neck of the die without the proper equipment "BUT"................................

1. Turning the necks would have the same effect along with polishing and reducing the diameter of the expander ball.

2. Plus if you order the Forster expander button and spindle unit that fits RCBS dies you will also reduce your neck runout.

The spindle has a thick rubber washer under the lock nut that allows the spindle to float and self center in the neck of the case.
The expander button is located high on the spindle and the expander enters the neck of the case while the case neck is still inside the neck of the die. Meaning the case neck is "centered" and "supported" in the die and the expander can not pull the necks off center and induce runout.

NOTE: More reloaded cases have excessive neck runout because the expander spindle is locked down off center than any other reason.

Bottom line the Forster full length dies or dies equipped with the Forster spindle unit produce less runout than any full length die I have ever used.

 

[boltfluter]

+1. Forester makes some of the best dies that are available today.

Regards, Paul

www.boltfluting.com

 

[Clint M]

I will look into the floating stem idea that makes perfect sense.....like a duhh moment why have I not already thought of that. I have a few Lee dies ( I just use the collet) if I'm not mistaken Lee uses a o-ring on top of the seater die or the collet die.

I have a collet chuck on my lathe which I have turned some necks just enough to clean up 70-80% way easier than the manual trimmers I have used in the past. Thanks for the tip..