Just started reloading for the 2nd go-round on my new 338 win mag and took a measurement with the Stoney Point Head & Shoulders Gauge. The once fired brass was WW (which I am developing the load with) and the new brass is Norma which I will load once I settle on powder, bullet, etc.

Once fired measures 4.122"
New Norma brass measures 4.100"
New WW brass measure 4.092"

That is a whopping .030" that the shoulder moved forward on the WW brass and .022" that it will move on the Norma.

The once fired is not tight in the chamber and from experience, the shoulder will only move imperceptively before it gets harder to chamber and the shoulder needs to be pushed back.

This is in a new Beretta Mato and those barrels are made by Lothar Walthar and should be chambered correctly.

What are the chances that the new cases will shoot to the same POI as the loads developed in the fire formed cases?

Woods,
After you have fired the new case the first time, neck size the case, ie, bring the die down until it is just shy of the shoulder. You should see a slight swelling of the neck above the case shoulder, and then the resized portion of the neck.

Resizing this way does not set the shoulder back or work the brass and that little bulge "centers" the case in the bore on chambering.

After you have resized, trim the case and you are ready to go for about three firings. When the rounds get hard to chamber, full length resize and start over.

You reloads should be more accurate than the first firings, and I'd expect the point of impact to change after initial resizing, but not much.

I find that case length and seating depth really influence accuracy. To squeeze the last little bit out, on the WW brass clean the inside of the touch hole and on both makes of brass clean the primer pockets before reloading. Kudude

I just got a new Savage in 300 win mag that will match that exactly. Crazy thing is I set my die to bump the shoulder back .003" from the "new dimension" and figured I better get ready to trim. Found out I still had .005" to go before trimming....go figure. We'll both have to keep an eye open for cracking ahead of the belt. Best to load the first loads mild.
Re accuracy...it's hard knowing how much it might be affected....only the guns will tell us.

Thanks kudude

I use a Lee Collet Neck Sizer and put a washer on top of the shell holder around the case and it neck sizes, leaves the neck chamber size just above the shoulder like you said, and I don't have to put up with the expander ball, lube in the neck, etc.

Just am always amazed at the headspace of new cases and how they can be accurate at all.

quote:

Originally posted by woods:
Once fired measures 4.122"
New Norma brass measures 4.100"
New WW brass measure 4.092"

That is a whopping .030" that the shoulder moved forward on the WW brass and .022" that it will move on the Norma.

It is quite amazing what brass will handle, isn't it.

Your numbers above illustrate 1) how large some chambers are cut - in particular this is often seen in belted magnums, where manufacturers "hide" behind the fact the headspace is established on the belt. 2) how brass manudfacturers really have to deal with chambers cut in all possible sizes, and therefore tend to keep their brass towards the small side, to make sure it chambers in all guns when new...

If you want to avoid the initial stretch of the case, you'll have to introduce a false shoulder before you fireform in your chamber. Neck up, and then neck down again, leaving a part of the neck the larger size. Now you can get the brass to headspace on this false shoulder for your initial fireforming.

Worth the extra effort?? Who knows?? Brass seems to hold up pretty well, in spite of what we ask it to do. Besides, being in the US, brass like this is cheap, and supply limitless...

- mike

If your measurments are correct the chamber to the shoulder may be out of spec. In fact way out of spec.

I had a Ruger #1 in 7mm RM like that and thats how I got the drawings with the actual tolerances of the chambers and cartridges. I kept that barrel however for decades and delt with it but it always bothered me. I made brass from 300 WM's and thats what I suggest that you do if you keep the rifle.

The first thing to do is to try to return it for warrantee repair.

"A bad barrel is forever"

I had seen as much as .028" short in new brass. You take the championship!

For the reasons you've discovered, years ago I started buying 358 Norma Magnum brass then sizing it back to .001" short of the shoulder. Amazing how much longer that brass lasts. As a matter of fact I've never lost one of those cases to incipient case separation. I've had to dispose of it because of expanding primer pockets, usually at just under 30 reloads. The Norma brass is about .040" longer in the body than our domestic 338 Win Mag brass.

For "belted" magnums (I only have 1), for the first firing, I will load a moderate charge and seat the bullet almost to the lands. This give me a case that hopefully won't stretch. And makes the case headspace on the shoulder rather than the belt.

With a Ruger #1, cartridge length is not a problem. If using a rifle with a magazine, I just single feed that first loading.

Then I neck size only just to the shoulder. If they get hard to chamber, I will barely bump the shoulder back but not do a full resize.

It's worked so far.

But with that much change in your case, I think I would have it checked by a 'smith.

Some other measurements:

New 270 cases 4.038"
Fired 270 Sako cases 4.045"
Fired 270 Browning cases 4.048"

New 300 cases 4.256"
Fired 300 Sako cases 4.270"
Fired 300 Mato cases 4.272"

New 30-06 cases 4.044"
Fired 30-06 Sauer 4.050"

Those new cases were also Norma

Guess which rifle is the most accurate. If you guessed the Sauer, you'd be wrong. It is definitely the least accurate. The most accurate is a tie between the 270 Sako and the 300 Mato.

I shot this group with new brass in the 300 Mato, the one on the right is 4 shots in the black square, the others at the bottom are spill over from another gun on the folded target below



So I guess it doesn't matter

quote:

Originally posted by woods:
took a measurement with the Stoney Point Head & Shoulders Gauge. The once fired brass was WW (which I am developing the load with) and the new brass is Norma which I will load once I settle on powder, bullet, etc.

Once fired measures 4.122"
New Norma brass measures 4.100"
New WW brass measure 4.092"
...So I guess it doesn't matter

Hey Woods, Darn near ANYTHING that Stoney Point thingy tells you - doesn't matter.

quote:

Originally posted by Hot Core:
Hey Woods, Darn near ANYTHING that Stoney Point thingy tells you - doesn't matter.

Yeah, I guess I need to learn to live in the dark or get real good at antiquated methods like you!!

Hey Woods, I do like "venerable, time proven" Methods.

I've been thinking about those measurements you made and they are indeed interesting. I don't think any of my "Classic Methods" would have caught those differences.

But, it really does help explain why my Elders believed in Fire Forming, or necking down from a larger Caseneck to get a good fit and thus had me doing it(which I still do).

In my situation, I suppose my "Historic Methods" of reloading end up eliminating that variance.

Sure glad you mentioned it because it has been a good mental exercise. And a great observation on your part.

Now you can throw that thingy away.