Loaded runout vs neck runout before loading

[dstoenner]

What

What I meant was I resized a case with stem and ball removed and got good concentric necks. So that would mean stem, ball or both are the problem . So what to try next? New stem or carbide ball or both? Is there any way of checking before I place an order?

This is where I got with my 260 Remington. I pulled the stem and hence the expander ball and bingo the cases were coming out with the same low levels of runout as they came out fired. So then I unscrewed the expander from the stem and tested that. Runout was still staying low. Only problem was that my neck tension was pretty high, like about .006 IIRC. That is when I bought my first FL bushing die from Whidden. I had been using a FL Whidden die on my 6 BR with great results so I decided to stay with Whidden. I am not sorry. Before I got the Whidden FL bushing die, I had tried every FL Sizing die from RCBS, Redding, Lee collet die and Forester floating stem with high expander. None of these got my sized case runout in the 1's My last loading of my 1 group of Lapua cases with 7 loadings on them I got 52 out of 93 cases with .001 loaded runout and maybe another 30 or so at 2 mil runout. I admit I was blown away.

So to your question. I would remove the expander and put the stem back in. Just be careful about your decapping pin being un supported unless you have a cap to put on in place of the expander. Prove to yourself that it alone is the issue. Once you know that then you can decide what your next step is.

HTH

David

 

[davecb]

I removed the stem and expander from my Whidden fl bushing die being I decap with a dedicated decapping die only. Is there any drawback to what I'm doing? I still see runout that I have trouble getting rid of? Some are dead on and others are around .003-.004. I am seating with a Sinclair/Wilson micrometer seating die using a 21st Century press. I anneal between every firing.

Dave

 

[Bart B.]

Dave,

Is the bushing diameter between 1 and 2 thousandths smaller than loaded round neck diameter?

Redding has an FAQ subject stating their tests show most runout issues are caused by crooked case necks after sizing. My own tests agree.

The more force it takes to seat bullets, the more necks can bend. Especially when case wall thickness is more uneven in the shoulder area.

 

[dstoenner]

I removed the stem and expander from my Whidden fl bushing die being I decap with a dedicated decapping die only. Is there any drawback to what I'm doing? I still see runout that I have trouble getting rid of? Some are dead on and others are around .003-.004. I am seating with a Sinclair/Wilson micrometer seating die using a 21st Century press. I anneal between every firing.

Dave

Personally i have seen Whidden dies straight as an arrow. You said you had a FL bushing die. So to remove the stem you had to take it out from the bigger part that holds the bushing. When you screw that back in do you tighten it down to where it contacts the bushing and then back if off just a little so that the bushing floats?

If you have done that then do you measure a case before sizing and then after?

If you have verifiable case goes in low runout and comes out higher then I would be calling Whidden to see what they ssy because you have quantifiable proof something is wrong

David

 

[davecb]

The neck on a loaded round is .290 and I'm using a .289 bushing. When I seat a bullet, it seats easily. I had to remove the expander just to get my dial to read(21st Century arbor press). When using the expander, It would not read on the scale at all. Without it, it seats at around 15 lbs.

I will check my die to be sure the bushing is floating. I'll do some troubleshooting this weekend if I get the chance and report back.

Thanks for the info guys.

Dave

 

[Dusty Stevens]

If you use a bushing dont use an expander. And make sure that bushing floats like you said. When you withdraw the case from the die if it touches anything youre just backing up again. On a whidden die use the knurled piece instead of the expander to hold the decapping pin.

 

[Hanbleceya]

Forster hones their die necks for $12 each. Any decent 'Smith could do it.

Use a Flexhone brush correctly in an electric drill and a hole micrometer to do and measure your own dies.

I would not use undersize expander balls. Undersize case mouths will be smaller and scrape off bullet jacket copper unbalancing them. The extra force needed to seat bullets can bend case necks.

And their seater dies hold everything in alignment better.

 

[Bart B.]

And their seater dies hold everything in alignment better.

They use the Bonanza seating die specs 'cause they got them from Bonanza.

Having measure several 30 caliber seater die's bullet chambers' diameters, my 30-338 Bonanza has the smallest one. Biggest is the Wilson 308 Win chamber type for arbor presses.