Hello all , here are the facts ,
Hunting rifle
300WSM - Remington brass
REDDING FL DIE - (polished the expander ball)
Imperial wax lube - case necks lubed as well
Sinclair bump guage .
Now... a new case measures 1.720
my fired cases measure 1.740
so im thinkin set back the shoulder to 1.738
per instructon -
Now the bolt WONT close on the sized cases , it WILL close (some slightly stiff)on my fired cases .
To get the bolt to close i have to push the shoulder back all the way to 1.723.5
the bolt closes with the ever so slightest amount of pressure - feels better to me than loosey goosey .

Is the expander ball pullin the shoulder back forward of the datum line ? i dont get it .
i figure the case is stretching but where ? everything checks out , neck ,oal ect..

Someone please help my simple mind .

What are you measuring the cases with and what is the datum circle diameter used in the measuring tool.

Im using a Sinclair "bump guage"
From their website ,
"Are machined to fit particular shoulder angles of cartridges. Rather than measuring to the datum line, these gages indicate off the shoulder of the case to get a better measurement for critical assessment of how much you are actually sizing your cases. We usually recommend between .001 inch to .002 inch bump for bolt action rifles. " .

You are using lube inside the neck?
Does it take alot of effort to get the expander ball through the neck?
I can only think right now that your assumption that the expander might be pulling the neck up could be correct.

MERCULA
In a word yes.
Try comparing your measurements of fired brass vs. resized brass. Using your bump gauge.
I hate expander balls. But some times must live with them.

muck

should I run the sizing die without the expander ball ,
then switch to a mandrel die to expand the neck?

The Sinclair gauge is giving you an erroneous reading on fired cases of 1.740". Might be some part of the fired case is catching and holding the gauge out.

Regardless, your chamber is the ultimate gauge and when you have a slight crush fit then you are in the right place. I often wondered if that could happen with gauges that had a bearing surface on the entire shoulder rather than on one datum line like the Hornady.

I would put some black felt tip pen ink evenly on the brass and chamber it both ways and see where its rubs the ink. Bumping it is probably making the shoulder fat

I once had similar problems W/an 8mm-06 A.I.

I found that the seating die was threaded too far into the press. (the die body, not the bullet seating plug itself)

The die was pushing the whole case neck back creating a bulge where the shouder meets the main case body.

I backed out the die half a turn, screwed down & locked the jam nut, then readjusted the bullet seating plug for proper OAL.

No more problems.

I think Woods (on two forums)hit it, this thing is bunk .
would a guage that usees the actual datum line work better in theory ?
Edit -
ok here is a fired case put in sinclairs bump guage -you can see the line where its taking its reading - where the neck meets the shoulder.

The tangent point where the shoulder meets the kneck is a bad place to measure....to many variables.
The mid-point of the shoulder is a good place.

I have had to F/S my WSM's to get an easy bolt close.

The WSM family doen't have alot of body taper.
F/S isn't a must but is needed for most.

I would email that pic to Sinclair so they know there is a problem with the tool, and to see if they can make it right for you. If it's not worth mailing it back to them for repair you might ask them to send you something else of similar value to compensate you.

Before you do anything drastic, take a Q-Tip
and lightly lube inside the with Imperial die wax at the shoulder neck junction. That cures a lot of expander pulling problems.
Good luck!

For what it is worth, I had the same trouble with reloading a 7mm wsm. Even when I screwed the sizing die the whole way to touch and cam-over the shell holder with the ram up, my fired cases would not chamber. I fixed my problem by simply grinding the shell holder face a couple thousands so the die could be turned in a little more. This bumped the shoulder back a few thousands more and the cases chambered easy. It worked for me. Shell holders are cheaper then dies. Daryl.

Datum line should be somewhere near the centre of the shoulder, not where it joins the neck.
As 86thecat said; send that photo to Sinclair.

DIs says,

quote:

Even when I screwed the sizing die the whole way to touch and cam-over the shell holder with the ram up, my fired cases would not chamber. I fixed my problem by simply grinding the shell holder face a couple thousands so the die could be turned in a little more. This bumped the shoulder back a few thousands more and the cases chambered easy. It worked for me.

Had the same problem on my 300WSM. Machined .015 inches off the shellholder and now I have .002 inches headspace when I set the die .0025 inches away from the shellholder. Every case fits so closely the bolt handle doesn't move even the tiniest bit when a round is chambered. I resize and check every case for fit before I reload it. Having an MRC M1999 with the easy system that rifle has for taking out the bolt and removing the striker assembly makes checking easy...

[QUOTE]Originally posted by woods:
The Sinclair gauge is giving you an erroneous reading on fired cases of 1.740". Might be some part of the fired case is catching and holding the gauge out.

QUOTE]

I agree, it's possible that the spent primer is above flush and giving a false reading. Try punching out the primer without sizing(universal decapping die) and measure again.

quote:

Originally posted by MERCULA:
To get the bolt to close i have to push the shoulder back all the way to 1.723.5
the bolt closes with the ever so slightest amount of pressure - feels better to me than loosey goosey

How does it shoot at this size? That's the real question isn't it?

I had a similar problem reloading 308Win with a neck sizing die I was using. Most of the cases wouldn't chamber after being neck sized. I coated one of the cases with black ink and watched where it was catching my chamber and it looked like the body/shoulder junction was just a fraction too fat. All the cases measured the same as near as I could tell so there was only a fraction in it.

I concluded that the expander ball in the neck sizing die was a bad fit for the necks and so was pushing the case a tad out of shape. The expander ball was certainly "tight" to push into and pull out of the case. I haven't used that die since and all has worked well, though I have basically been full length sizing since. I have recently started experimenting with the Lee collet neck sizing die and so far all the rounds made with it will chamber.

The Lee collet dies are inexpensive if you were inclined to try one, I wasn't really expecting mine to work as I'm reloading for a Blaser R93 and lots of clever people say to full length size for them at all times.