Help! my neckdie gives runout

[artemistrad]

Hi,

I have a bought a RCBS neckdie for the 5,6x50Rmag but now i find out the die is cutting into the brass (mostly on one side) and it gives terrible runout on the neck (it offcenters it). I do lube but don't understand what is going wrong? The press i use is the CO-AX from Forster...
Who can help me am scared to go on, all my RWS brass will be ruined this way.

thanks in advance, greetings, Mark

 

[Gunpoor]

I never use lube with a neck size only die as it is not needed. I have only neck sized for the 264WM and 30/06 but have never had any issue with runout. Are you sure the shellholder is fully seated in the ram? It seems to me that the case is not centered in the press and this could be causing the case to enter the die at an angle. Have you tried using a FL size die to see if their is runout with it. It is unlikely but the die could be defective, and I am sure, if it is, RCBS will make it right under there warranty.

 

[artemistrad]

I tried a Full lengthsize die on same cartidge, no problem at all, fully centred! Gr Mark

 

[Brewer]

sounds like you need to get ahold of RCBS to get another one for free. I cant imagine that you would have trouble getting another one that should get you close enough you will have to measure to see the runnout.

 

[g0rd0]

right, if your fl die works and your nd is running out on 1 side then CALL rcbs! They are good and will set it right, give em a call

 

[jrock]

My RCBS neck sizing die gave 0.002-0.007" neck runout. FL die was fine at less than 0.001". Sold the RCBS neck die and got the LEE collet one which gives less than 0.001".

 

[FearNoWind]

I've used RCBS dies for fifty years. Rarely had any problem but when something didn't work quite right they made it right - highest customer service I could ask for right up until last month when they took care of a decapping die issue for me.
Give them a call.

 

[artemistrad]

Hi little update here: RCBS says it is because i don't neckturn the cases! But i have little doubt if that's the reason, specially by RWS cases wich are very consistent.
But: maybe there is one thing that can cause it also, maybe someone can help me with that;
I only necksize the neck 3/4th of the length of the neck, so could it be the reason for having this problem? Should it be better to necksize till on the shoulder of the case?

Who knows?

Greetings, Mark

 

[jrock]

Neck turning or not shouldn't have anything to do with it. You could measure your wall thicknesses to see if there are any major differences on the side that is getting marked but I think it's a waste of time. Sounds like a bad die to me. Look inside with a light and see if you see anything unusual. Also, did you clean out the new die before using it?

 

[artemistrad]

Hi,

Yes i cleaned out the die
Will check with a Light the inside, the die really cuts of brassmaterial from the neck, as if its scharp. Gr Mark

 

[artemistrad]

For all the guys who have the same problem, maybe i found the solution!

I did testing with old cases. I could solve the issue as follows:
- I loosend the decappingpin/mandrel on the die, till now it was tight screwed on the die but i loosend it so it can move inside the die
- I only used some Forester Micro grafite powder on the inside of the neck, NOT outside.

With this Runout of the neck was around 0.0001"

So concrete: i think the decappingpin/mandrel is not fully centered in the die, the floating of the die itself in my CO-AX press seems not enough, also this is a more evident problem because i turned the decappingpin up so i don't get in the primerhole, as i have decaped all my brass before cleaning. Though the mandrel is still under the necksizing part!

Thanks for all the support till now.

BW the only answer to the problem i got from RCBS was:
Neckdie is only usable when you neckturn, otherwise always use the FL-die.
This seemed a little to much a cutoff in the solution.

 

[jrock]

Glad you got it to work. My next suggestion was to lube the expander ball, so glad you figured it out.