I have a Forster Co-Ax press and I have used Redding, Hornady, and RCBS dies. And it isn't related to only one caliber. It seems to be all calibers that I load for. If I size the case but don't have the expander in the die the necks are perfect. But I get runout when I expand the necks. Some dies only give me .001" runout and some give me up to .005". When I don't use the expander I get .000". What am I doing wrong and what can I do to correct it? I would continue to not use the expander but then the necks are to tight to fit over the pilot on my trimmer. I hope this all made sense. If not let me know and I will try to make sense of it for you. By the way I have been reloading seriously since 1995 so I am not a newbie.
Case necks have runout after resizing
- Thread starter Underthegun
- Start date
- Location
- Prince Albert, Sk
Some have very consistent results with the collet type dies.
I like them, and they are really good for working the brass as little as possible.
I like them, and they are really good for working the brass as little as possible.
I tried that. It helped on the ones with alot of runout but did not eliminate it. And it made no difference on the ones with a small amount.
Try sizing with the expander stem removed from the die, then put it back in but left loose, and run your necks over the button on the upstroke.
Lyman "M" dies work well for this.
I beat runout by using Lee collet, Lyman "M", and Redding BR seater.
A max of 1.5 thou. TIR now, measured out on the bullet ogive near the tip.
Two thou. of neck tension works well for me.
Lyman "M" dies work well for this.
I beat runout by using Lee collet, Lyman "M", and Redding BR seater.
A max of 1.5 thou. TIR now, measured out on the bullet ogive near the tip.
Two thou. of neck tension works well for me.
The thickness of the brass on the case neck may be part of the problem. It is difficult to measure with a calipre but such a measurement on your worst brass may show such a problem. .001 runout is actually pretty good for almost any use, I'm usually more concerned with the bullet runout. Sometimes as well a particular case is just impossible to control runout and I simply cull it.
I've reduced this problem by sizing without the expander in place as you have done, then reinstalled the expander loosely and pushed it down through the neck in a seperate operation as opposed to pulling it up through in the normal way.
The shoulder of the case must resist deformation more in this direction I guess.
Now I just use a Lee Collet Die and that yields very satisfactory results.
The shoulder of the case must resist deformation more in this direction I guess.
Now I just use a Lee Collet Die and that yields very satisfactory results.
This is normal. Factory brass is not perfectly concentric. The best you'll get is something like Lapua brass. To correct this you need to outside neck turn the brass to a consistent thickness. Turning will reduce bullet runout, increase neck life and provide for consistent neck tension. By doing so I can consistenly attain less than 2 thou runout. Even so, there are cull brass which do not appear to be fixable and they get tossed.
Be sure to set up dies correctly as manufacturer recommendations. For example with RCBS, I first adjust the resizing die to down to touch the shell holder at full press and loosen the expander nut assembly. Then run a piece of brass into the die to deprime. Then set the lock nut on the die under pressure to ensure brass die alignment. Then run the press back up until the expander touches the shoulder. Under slight pressure I set the expander nut firm. What you are doing is setting up the expander to line up with your brass.
Hope this helps. Elky....
Be sure to set up dies correctly as manufacturer recommendations. For example with RCBS, I first adjust the resizing die to down to touch the shell holder at full press and loosen the expander nut assembly. Then run a piece of brass into the die to deprime. Then set the lock nut on the die under pressure to ensure brass die alignment. Then run the press back up until the expander touches the shoulder. Under slight pressure I set the expander nut firm. What you are doing is setting up the expander to line up with your brass.
Hope this helps. Elky....
