custom opening neck area of die question

[MildBill]

I am thinking I might get the neck on a forster neck die opened up a little bit to minimize brass working.

trying to figure out how much to open....

0.002 smaller than the ball on the stem will open it up to?

what are the recommendations?

thanks

 

[Barlow]

Using a case fired in that rifle, measure the OD and ID of the case neck and write it down. Set up your die with the expander ball removed. Run your case into the die and measure the OD and ID, and check the numbers against the fired case. If you want .002 bullet tension subtract correct amount to get there. And or call Forster and talk to the tech (can't recall his name) with your numbers and he will give you good advise. There is a parameter of measurements it has to fall into or it can't be done. They have done a 6 Dasher and a 257AI for me, and I'm well satisfied with them. Hope this helps. Barlow

 

[Scott Harris]

Measure the diameter of a loaded cartridge at the neck and subtract .002 to .004 depending on how much neck tension you want. Your rifle's chamber dimensions don't really matter when it comes to selecting the correct die neck size: it's the loaded cartridge dimension that matters. Forster can hone the necks of their dies to the dimensions you specify.

 

[MildBill]

so it appears I should not be using the expander button if I have it opened up?

just opened up enough to be a few thousandths smaller than a loaded round?

will that make a difference if I do not neck size as to whether to use the expander button or not.

with this particular rifle the neck is 0.005 bigger than the loaded round after firing. trying to minimize brass working here.

 

['Freak]

I figger if you were to get the die opened only enough that the die will still squash the neck ID down so it’s a touch under the expander’s OD then with the expander ball or a separate expander mandrel being the very last thing touching from inside the neck taking its ID back up to where it’s ready to accept the bullet then it’ll also be putting any concentricity problems or other neck wall surface inconsistencies back on the exterior side where they won’t be messing with grip on the bullet or offsetting the bullet from centered in the case.

 

[dkhunt14]

Why not send the die to JLC and have a bushing put in? With a bushing you can change sizing. If the die is hardened you will have a hard time opening it up. He charged me $35.00 and had it back in a week. Matt

 

[Canadian bushman]

+1 to dkhunt

I just reamed out the necks .004" on some redding dies and i had to regrind the reamer after every die.