Die to press alignment

[TackDriver284]

I use Redding full length non bushing and bushing dies along with competition seating dies on a Redding Boss press. I use the trusty Hornady lock rings to secure my dies. I have no issues with accuracy with my rifles, but I have seen some runout of .003" after using the bushing sizing die which is not major runout but just a thought on how to reduce runout. I put an o ring between the die and press, unlocked the lock ring and backed it out about 2-3 turns, and hand tightened the die against the o ring on the press, lubed a case and sized, measuring, and kept screwing in the die until .002" bump was set. Locked the Hornady die ring, marked the location on the press and die so it lines up each time I screw in the die. Checked runout on a .308 15X fired case which was wet tumbled for the first time, and it measures .002" run out which is reasonable on a no turn neck. With the O ring / die, pushing the die front and back gives it a small to and fro movement, compared to without the 0 ring.
Has anyone had any success with the O ring or has it not shown any difference?

 

[SJB358]

TD are you saying you’re seeing .003” runout after a case is sized of .003” run out after seating a bullet?

The reason I ask is I had a few sets of dies that would pull the necks crooked when I would extract the case from the sizer die and the neck pulled over the expander.

All I did in those cases was loosen the expander rod a bit so it had some movement so the case could pull straight over the ball, versus the rod being tight and pulling the neck out of wack.

I’d imagine your O-Ring does about the same thing.

 

[phil]

TD are you saying you’re seeing .003” runout after a case is sized of .003” run out after seating a bullet?

The reason I ask is I had a few sets of dies that would pull the necks crooked when I would extract the case from the sizer die and the neck pulled over the expander.

All I did in those cases was loosen the expander rod a bit so it had some movement so the case could pull straight over the ball, versus the rod being tight and pulling the neck out of wack.

I’d imagine your O-Ring does about the same thing.

Never dealt with this myself, but is there a way to orient the shell holder to allow for self-adjustment of the case as it’s pressed in?
If it’s the expander ball and stem, and they aren’t bent, I’d throw the expander away and use a mandrel and mandrel die.

 

[SJB358]

Never dealt with this myself, but is there a way to orient the shell holder to allow for self-adjustment of the case as it’s pressed in?
If it’s the expander ball and stem, and they aren’t bent, I’d throw the expander away and use a mandrel and mandrel die.

No idea. I mostly use a Forster Coax which should help with the problem all the way around. I’ve just gotten into the habit of keeping the decappimg rod a bit lose, not really loose, just enough you can move the decappimg pin around with your finger. Some dies come with a rubber washer just for that reason I believe.

 

[phil]

No idea. I mostly use a Forster Coax which should help with the problem all the way around. I’ve just gotten into the habit of keeping the decappimg rod a bit lose, not really loose, just enough you can move the decappimg pin around with your finger. Some dies come with a rubber washer just for that reason I believe.

That’s one thing I like about 21st century Mandrels/Dies.
They can self align.

 

[TackDriver284]

TD are you saying you’re seeing .003” runout after a case is sized of .003” run out after seating a bullet?

The reason I ask is I had a few sets of dies that would pull the necks crooked when I would extract the case from the sizer die and the neck pulled over the expander.

All I did in those cases was loosen the expander rod a bit so it had some movement so the case could pull straight over the ball, versus the rod being tight and pulling the neck out of wack.

I’d imagine your O-Ring does about the same thing.

No, sorry for not being clear in the first place, I meant just the sized case neck on a RCBS CaseMaster to check neck runout, without the bullet seated in it. As for the expander, I never liked them for the reason you gave, I removed them all from my dies, I use a carbide expanding mandrel as a 2nd step after sizing. I use an expanding mandrel .001" under bullet diameter, like a .307 mandrel for the .308 cases. I keep most of my neck tension to .001" , but I also have .002" mandrels.

 

[TackDriver284]

Never dealt with this myself, but is there a way to orient the shell holder to allow for self-adjustment of the case as it’s pressed in?
If it’s the expander ball and stem, and they aren’t bent, I’d throw the expander away and use a mandrel and mandrel die.

I use the Sinclair expanding mandrels.

 

[phil]

I use the Sinclair expanding mandrels.

The last Redding seater I had caused excessive runout.
For me anything over .001 is alarming, personally..
I use a an LE Wilson for that cartridge now, no more concerns.

 

[SJB358]

I use the Sinclair expanding mandrels.

Same here depending on the cartridge.