Noob question about die component concentricity

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battlecry

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I just got my first set of dies this week and I'm somewhat puzzled.

The Redding .223 Type S full body sizing die had a visibly severe runout in the neck expander button mandrel. I thought the mandrel was bent, but after diassembling the die to check, I see the the mandrel is true.

The threading between the mandrel to the depth adjustment knob and between the knob and the die body is (to me) surprisingly loose, which accounted for the runout.

I did not have a neck bushing in the die. Just found out I needed it. I suppose this would help me align things.

How do you thread and lock everything up so it is all concentric?
 
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If this is a Type-S die, then you can use it without the neck expander plug. Just find the right neck sizing bushing and go with that. I sometimes use inside expander, but do so with a carbide button because it gives straighter ammo.

The theory is that the inside expander self centers as it goes through the neck. Maybe so, maybe not, but if it drags excessively from too tight a fit or lack of lube, then non-concentric necks result. That is why I use a carbide button and lube the inside of the neck, too, when I do it.
 
Ditto on the carbide buttons, but I don't lube the neck. If I am getting srious about accuracy I use carbide neck bushings. They are more expensive than Reddings coated ones, but are slicker.
 
battlecry,

Yes, ditch the decapping pin with expander ball altogether. Use a universal decapping die to remove spent primers. If you are loading for a boltgun, get a bushing .002" smaller than your loaded round's neck diameter; with an autoloader or rifle with a tubular magazine, go .004" smaller.

Don
 
Try this:

Use a universal decap die before you size.

Push a case fully into the Redding sizer.

Screw the decap rod up, until the top of the expander plug stops at the neck, then screw it back down until the expander is about 1/16th inch below its highest point. Now, starting from this position, the expander will begin its work as the case is withdrawn and while the case neck is still held centered in the die.

Do not tighten the expander plug stem & nut at all, let the expander "float" into correct alignment as the case is withdrawn over it.

OR, if you feel you must secure the stem to feel comfortable:

Place a small rubber "O" ring under the stem's locking nut and snug it just enough to hold position but still allow the stem to shift into correct position under extraction tension. The "O" ring will prevent firmly locking the expander out of alignment and without risk of losing adjustment.
 
Thanks for the tips guys.

USSR, the pin is history. Just ordered the Lee universal decapping die.

Ranger, just polished the button, so I'll try the o-ring for now. My brass is pretty hammered after ejecting the case. I'll be buying some virgin stock this fall and I'll be loading some without the button and see how they work.

Bad and Walkalong. I'm looking at the Sinclair catalog for those carbide buttons. It does seem like they would self-center and work.

Thanks again, guys!
 
>It does seem like they would self-center and work.<

Great, but use Ranger's setup/alignment procedure; it will help, too. When you do use his procedure, pick a case that has a well-centered flash hole.
 
If you use my system of raising the decap stem, neither flash holes nor decap pins will matter. The expander will be so high in the case the pin won't reach the web.

Polishing the expander button always seems to help reduce neck stretching a little. Even better is running a brass bore brush in the neck to remove excess carbon and then spinning a bit of lube (Imperial Die Wax or Kiwi Neutral shoe wax work well) inside the neck with a Q-tip.

Good luck!
 
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