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Old May 3, 2013, 02:49 PM   #1
omnimedic
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Sizing/headspacing

I have recently gotten into handloading, both for the cost and the accuracy aspects. I'm having trouble with the sizing and spacing on my loads. I'm trying to reload once-fired .308 brass, and have discovered that the bolt won't close compeltely on some of my cartridges; with it, I see brass rubbing off on the bottom of the bolt, as if the bolt is scraping across the rounds in the internal magazine (Remington 700).

I checked OAL when I ran the batch, and that's not the problem; instead, I have discovered that diameter of the case just below the shoulder is 0.003 too big; this is consistent across most of my cases.

Is this an issue that can be fixed by adjusting my dies (RCBS dies/press), or do I have a bigger problem?

TIA,
Omni
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Old May 3, 2013, 03:14 PM   #2
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Omni, It sounds like you have your seating die down to far, for example: I use a nickle as a feeler guage for all my seating dies as to not crush the shoulder on any cases that may be a tad longer than others. I adjust the seating die down on this nickle just so it bumps the die and then tighten lock ring. If you want to use a cartridge that you already have loaded to adjust seating stem, just loosen seating stem locknut and twist stem counter clockwise just a few turns then run your loaded cartridge up into die making sure your ram is in it's upmost position then adjust seating stem down until it stops. Dont do this on a cartridge that has been crushed already. This is one remedy that's easy to duplicate with all seating dies.
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Old May 3, 2013, 04:59 PM   #3
omnimedic
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That sounds like how I adjusted my bullet seating die: took a factory loaded cartridge, ran it all the way up with the ram, them screwed the seating die down until it touched, and make fine adjustments until the OAL on the reload was the same as the factory cartridge.

The +0.003 diameter I referenced is as measured on cases after they have been primed but before powder and bullet seating. I think the problem is somewhere earlier in the process, like during the depriming/sizing step....
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Old May 3, 2013, 06:01 PM   #4
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Problem #1 - If you are not doing this already, ...

- Unscrew the seating stem many, many turns (waaaay out)
- Now screw the die body down until it hits a sized/unloaded case that's all the way up on the ram
- Unscrew the die to get it way off that case at least 1/2 - 3/4 turn. Lock it.
- NOW screw the seating stem down to get the proper OAL.

This way there is no possibility of inadvertently crimping while the bullet is still moving into
the case--and thereby crushing the shoulder a scoch.


Problem #2 - a Bolt face that is not perfectly square to the case head can/will shave "flecks" of brass.
Not unusual, but that's not keeping the bolt from closing. That sounds like headspace.

Problem #3 - Are you full length resizing? ... Sizing die all the way down to contact
the ram/case-holder, and then 1/16 turn more to overcome any flexing in the press?
De
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Old May 3, 2013, 06:30 PM   #5
Brian Pfleuger
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Quote:
Originally Posted by mehavey
Problem #3 - Are you full length resizing? ... Sizing die all the way down to contact
the ram/case-holder, and then 1/16 turn more to overcome any flexing in the press?
I must take some exception with this instruction. While it matches the instructions that comes with most die sets and will likely make functional ammo, it is not best practice and is not good for best accuracy or brass life.

Properly full-length sized brass will have the shoulder "bumped" back between 1 and 2 thousandths of an inch from the maximum "as fired", unsized dimension.

To accomplish this, the reloader needs either the Hornady headspace gauge set or a bushing that is longer than the neck of the case and is the approximate diameter of the center of the shoulder:

Zero your calipers on the bushing and then measure the shoulder length of a bunch of fired, unsized cases. Better if they have been fired and neck-sized only 3 or 4 times. The longest ones are very close to your chamber dimensions.

You should adjust your sizing die to move the shoulder back no more than 0.002. Note that first the shoulder will actually grow longer, as the sides are squeezed and the shoulder has nowhere to go but up. As you adjust the die down, it will finally contact the shoulder and "bump" it back.

You need to make the adjustments in very small turns. Die threads are 14 thread pitch, which is 14 turns to the inch. That means that one full turn is 0.0714 and a quarter turn is 0.0178. Feeler gauges are helpful if you have them but trial and error works fine too, just takes a little longer.

Note that you're not really "bumping" the shoulder. The extra length is actually going into the neck... the case is getting longer. Be sure to check length after sizing and trim as necessary.
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Old May 3, 2013, 06:47 PM   #6
mehavey
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Quote:
I must take some exception with this instruction.
I'm just trying to isolate the problem by process of elimination for a new reloader Brian.

Once we've figured out where the enemy is, we will tailor the attack.
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Old May 3, 2013, 06:50 PM   #7
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Well... I suppose.
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Old May 4, 2013, 12:55 AM   #8
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OP says diameter of the case just below the shoulder is 0.003 too big and the bolt won't close on some of his cartridges. He doesn't mention a headspace dimension. I'm guessing from what the OP has told us so far that (1) the bolt isn't closing due to too the case's headspace being too long, and (2) the case below the shoulder is .003" to big because the sizing die set too high. I think adjusting the sizing die as mehavey suggested in his #3 will solve both problems.

And I tend to agree that first, just get it to work, then fine tune it.
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Old May 4, 2013, 06:49 AM   #9
Bart B.
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Omnimedic, are you using a neck sizing die?

Or a full length sizing die?
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Old May 4, 2013, 08:02 AM   #10
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Someone explain ( in easy terms) how he could possibly crush his case to the size he's talking about, while resizing. Other than totally botching setting up his die, I can't see how this could cause his problem.
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Old May 4, 2013, 09:39 AM   #11
mehavey
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1. Case isn't crushed (if it's actually crushed) during resizing. It's crushed if/when the seating die's crimp ledge starts crimping into a non-cannelured bullet before the bullet is fully seated. When the crimped-bit bullet then moves down, the the case shoulder sides take gthe hit -- producing shoulder interference)

2. On the other hand, if the sizing die is left a scoch too far out, it squeezes the case sides in (lengthening the case/shoulder dimension) and the shoulder itself is left too long. (Headspace problem)

- OR -

3. That once-fired 308 brass is mil-surplus from a machine gun and might need to be small-base re-sized the first time out.

I'd proceed 1, 2, 3 in checking it out -- UNLESS a case right out of the re-sizing operation (no priming/no powder) won't chamber or chambers hard. Then it's #2 (likely) or 3 (less likely/but possible).




BREAK BREAK.
My Model 70 has minimum headspace. Winchester brass requires that I go shell-holder contact +1/16 with the die to chamber. My Lapua brass (softer shoulder/annealing) requires only ordinary die contact. I have to set each up differently, using a Stoney Point headspace gauge to confirm 2.044" at start.

(Ain't this fun?)

Last edited by mehavey; May 4, 2013 at 10:54 AM.
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Old May 4, 2013, 11:00 AM   #12
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Sometimes first fired brass can cause a problem on another's reloading bench. As you know first fired brass memorizes its very first chamber's profile. That other rifles chamber may have had excessive headspace issues and other weird things going on. Maybe its brass grew in length beyond suggested reloadable tolerance.
So the very first thing you need to do is measure or mic your empty brass's Length. Make sure too trim all your brass to the same length. Tip: {When I trim. I trim all my brass to their suggested Minimum Length}

Or as previously mentioned a Hornady Comparator tool. (used to purposely set any F.L Resizing Die to a correct working measurement or tolerance when the die is fully mounted in your press. Simply put. {Resolves a headspacing problem. Due to the shape or form your brass's shoulder area swelled to be in its intial firing and corrects & reforms that shoulders shape back to its normal proper tolerances.}

You could try using a Small Base resizing die which more than likely could resolve your issue. Basically put. Just squeezes the entire shell to a smaller allowable tolerance. Which helps in feeding, fully chambering, and bolt lock-up. To purchase either tool new. They both cost about the same. But there is a plus with a Hornady Comparator tool. It can be used on other caliber Resizing die set -ups. The Camparator tool initially is a bit tricky to learn and requires the need of knowing how to use and read a Vernier Caliper. But once you catch on to a Conpartor's use/operation. It's then becomes a piece-of-cake there after to use. And a very useful tool to have on any reloaders bench. Tip: {Many times I've seen used 308 Small Base resizing die/die sets being auctioned on EBay.}


S/S

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Old May 5, 2013, 07:00 AM   #13
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Sure Shot Mc Gee claims:
Quote:
. . .first fired brass memorizes its very first chamber's profile. That other rifles chamber may have had excessive headspace issues and other weird things going on. Maybe its brass grew in length beyond suggested reloadable tolerance.
I disagree.

When first fired, a new .308 Win case is a couple thousandths inch smaller in diameter than the chamber. Its headspace (head to shoulder) is a thousandth or so shorter than chamber headspace and is usually greater than when new. It springs back from hard contact with the chamber walls.

It's also a couple thousandths shorter in case length; head to mouth. It gets shorter as it expands against the chamber then shrinks back a little, but never to original diameters.

How much that first-fired new case changes size depends on the difference between its dimensions when new and the chamber dimensions. The metalurgy properties of the case brass also has an effect on how much its size changes. It will not fit in a chamber whose diameters in the body area are smaller than its new body dimensions.

Full length sizing that fired case makes it grow in length about a thousandth longer than when it was a new case. Its headspace is determined by how much the sizing die allows it to move. If the die doesn't set the shoulder back, sizing down the body diameters may push the fired case shoulder forward; sometimes enough to not allow it to be chambered back in the rifle it was first fired in. The sizing die's dimensions relative to the fired case dimensions effects the amount of sizing that fired case.

And if the "other" rifle had excessive headspace, that fired case fired in a normal headspaced chamber would easily fit in a chamber with more headspace; diameters allowing it.

Last edited by Bart B.; May 5, 2013 at 07:14 AM.
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Old May 5, 2013, 09:52 AM   #14
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Are you lightly lubing the case body and inside of the neck before resizing?
You can try double resizing by rotating the case 90 degrees and doing it a second time.

Is your barrel stainless steel? If so it might have a tight chamber.

Were these once fired cases from you own gun or did you buy once fired that were shot in a different gun?
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Old May 5, 2013, 04:26 PM   #15
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I'm with Bart B on this, though I won't say it the same way. With a case like this that doesn't have a lot of body taper, if you don't size the case enough, the shoulder will move forward and won't be set back enough - or set back at all. This isn't a problem usually with cases with more taper, like 270 or 220 cases. I think that the OP needs to not size less, but actually size a bit more, and set the die as RCBS instructions say. Of course, the objective is to set the shoulder back just enough and not too much, and sometimes the RCBS instructions will push the shoulder back too far, leading to case life problems. So, Brian's suggestion about using the proper gear to be able to determine the proper setback and arrange the die for that, is the way to go.
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Old May 5, 2013, 05:45 PM   #16
Sure Shot Mc Gee
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Without all the mumbo jumbo.

Quote:
S/S McGee said: Sometimes first fired brass can cause a problem on another's reloading bench.
The OP never stated or made clear where the brass was originally gotten or who fired it. (Be it someone else or him. Who knows? ) So I based my theroy on: The brass in question was fired originally by another person and not from the OPs weapon.

With that said I can't remember ever having the ability of chambering someone else's first fired brass directly into the chamber of my rifle and not have its bolt lock up without difficulty. EVER!!

"That's my story and I'm sticking to it!!"
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Old May 6, 2013, 04:47 PM   #17
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If It was my press, die and shell holder I would know if the case would chamber before I lowered the ram, there is something about the conflict between the case not wanting to be size and my presses ability to overcome the resistance. Then there is that part where I save a unfired, new, minimum length, full length sized case for reference.

Then there are barrels, I have barrels, a few new ones and a lot of take off barrels, then there are the barrels I remove the chamber from, all I have to know is what the definition of a minimum length sized case, all that is required for me to do is measure the protrusion from the chamber of a barrel before firing and again after firing, after sizing all that is required to do is drop the sized case into the take off barrel and check for protrusion.

I could dig through the drawers and dig out other tools and surround my self with nice tools, not necessary tools, just nice tools, again, if it was my press, die and shell holder I could tell if the case was going to chamber before I lowered the ram.

F. Guffey

Last edited by F. Guffey; May 6, 2013 at 04:48 PM. Reason: remove an a
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Old May 6, 2013, 05:03 PM   #18
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Then there is transferring, transferring dimensions of the chamber to the press. I eliminate the conflict between seating, off the lands and crimping, then there is COL, case overall length, some refer to the term as COAL, coal, case over all length. Again, I do not surround myself with a pile of nice to have tools, I transfer the dimensions of the chamber to the seating die when I adjust the seating die.

I made a seating tool that did does not have a die body, it has case neck and shoulder support, it is near impossible to wad the case up below the crimp unless the crimp is applied after the bullet is seated. Then we go back to Lyman when they were the sight company and now Dillon, both thought seating and crimping was a bad habit, again I use a transfer to adjust the seating die.

F. Guffey

Last edited by F. Guffey; May 6, 2013 at 05:04 PM. Reason: change an o to an i
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Old May 6, 2013, 08:05 PM   #19
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Sure Shot's claim:
Quote:
. . . . I can't remember ever having the ability of chambering someone else's first fired brass directly into the chamber of my rifle and not have its bolt lock up without difficulty. EVER!!
I've done it several times with different barrels.
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Old May 7, 2013, 09:18 AM   #20
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Sure Shot Mc Gee, Minding my own business, a reloader/shooter/etc. called from the range, seems a proud new owner with a Ruger chambered in 30/06 had 5 fail to fire out of a box of Remington ammo, I suggested they call Remington, I suggested they call Ruger, later in the afternoon the 15 fired and 5 failed to fire came here, no box and no name of the proud new owner.

We measured the fired cases, with the L.E. Wilson case gage, we checked the fired cases in my chamber gage, we checked the fired cases with my home made case length gage, the fired cases did not protrude from the L.E. Wilson case gage, we measured with a straight edge and feeler gage, the cases chambered in my chamber gage and the cases when measured for length were shorter than a go-gage length chamber chamber. The fired cases would chamber in any 30/06 chambered rifle I have, that would be 6+, in one chamber the fired cases would be .014” shorter from the shoulder of the case to the head of the case than my chamber in that rifle.

Failed to fire, 5 cases, we pulled them down, weighted the bullets, powder, cases and primers, if there was a difference it was less than .1 of a grain, I was impressed, we compared the fired with the fail to fire, we were impressed with the Ruger chamber.

At the range, everyone had an opportunity to attempt firing the fail to fire rounds, the primers were hit at least 5 times with 3 rifles, we installed the primers back into the same case they were removed from and fired all 5 one at a time in one of my M1917s, all know to have longer chambers from the shoulder back to the bolt face than the Ruger, all 5 primers were crushed and fired.

I had two 300 Winchester Mags, one was a non-Weatherby, the other a Model 70 Winchester, the non-Weatherby with the non-Weatherby chamber shot one hole groups, the Winchester shot patterns, cases fired in the non-Weatherby would drop into the Winchester Model 70 chamber like new ammo, cases fired in the Winchester could not be stuffed into a full length sizer die, or a small base die, of a forming die.

Winchester and I had words, I wanted a chamber that fit my dies or Winchester dies that fit my chamber, they suggested I was difficult at first then I became impossible.

They suggested, before they do anything with the rifle, I shoot it more. Long story.

F. Guffey

I have purchased cases from the firing range, normally in groups of 100 and or 200 because of the price incentive, purchase 100, get 10 free, when sorting cases it was not uncommon to be able to group the cases in 20s, again, my favorite case was the case that was fired in a trashy old chamber. That would be a case that was longer between the shoulder/datum and case head than a go-gage length chamber.
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Old May 7, 2013, 10:10 PM   #21
Sure Shot Mc Gee
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S/S Mc Gee said:.
Quote:
I can't remember ever having the ability of chambering someone else's first fired brass directly into the chamber of my rifle and not have its bolt lock up without difficulty. EVER!!
Bart B attempt to assert:
Quote:
I've done it several times with different barrels.
Well I guess we have a difference in opinions.

S/S
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Old May 8, 2013, 09:41 AM   #22
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Omni: "The +0.003 diameter I referenced is as measured on cases after they have been primed but before powder and bullet seating. I think the problem is somewhere earlier in the process, like during the depriming/sizing step...."

It's impossible to 'expand' a case shoulder in an FL no matter how the die is adjusted. Nor can he expand/swell anything in a seating die that hasn't yet been used.

Omni, if you DO have an over-size shoulder you have a defective die, get it replaced. I rather suspect you have no problem with the shoulder diameter but instead have a problem with insuficient shoulder set back. Try turning your FL down another 1/8th turn and size again; see if the cases won't chamber properly then.
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Old May 8, 2013, 10:42 AM   #23
F. Guffey
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“I checked OAL when I ran the batch, and that's not the problem; instead, I have discovered that diameter of the case just below the shoulder is 0.003 too big; this is consistent across most of my cases”

I have a leaver policy, I purchase a die, then! I apply the leaver policy, I leaver the way I founder, others grind, polish, lap and hone etc., bad habits, then there is the grinding the bottom of the die and if that dies not ‘get it’ they go for the shell holder and grind on it for a while, no one is accountable, RCBS should issue a ‘void warranty’ stamp for those that bubba-rise dies, back to no one is accountable.

Let us assume the die had not been screwed up (rendered scrap), let us assume the die is capable of returning a case to minimum length/full length sized (not bumped). Let us assume the case does not have more resistance to sizing than the RCBS press and die can overcome, that leaves us with determining if the case was returned to minimum length/full length sized before the ram was lowered. Before a reloader lowers the ram to remove a case it is possible to determine if the case whipped the press or if the press won and whipped the case. If the case won the case did not get stuffed into the die, the amount of the case that did not get stuffed into the die will be holding the die off the shell holder, the gap between the shell holder and bottom of the die can be measured in thousandths with a feeler gage.

The feeler gage can also be used in increase the ability of the die and press to overcome case resistance to sizing and increase the length of the case between the shoulder/datum and case head.

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Old May 8, 2013, 11:26 AM   #24
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Quote:
Bart B attempt to assert:

Quote:
I've done it several times with different barrels.
Well I guess we have a difference in opinions.

S/S
It's not difference of opinion, but a difference in luck. If the cartridge was fired in a chamber that is smaller than yours, in every particular, it will fit in yours as-fired. Otherwise it won't.


Quote:
Originally Posted by Bart B.
Omnimedic, are you using a neck sizing die?
This could easily explain it. Brass first fired in a loose chamber and run into a neck-only sizing die.


Omnimedic,

If you have a neck sizing die, you need a full-length sizing die. If you have a full-length sizing die, have you set it up as illustrated in this video? It is critical that after you have adjusted the die down to contact the shell holder that you place an actual lubricated case into the shell holder, run it up into the sizing die, then look sideways for a crack of light between the shell holder and the bottom end of the die. If there is one, then you may actually be increasing the headspace on the case. You then want to withdraw the ram and turn the die in a little (1/8 to 1/4 turn), and try again until the crack of light is gone. Then test again with another case to be sure it's still gone. If not turn it in another 1/8 turn and try again. Repeat with new cases until no crack of light shows with any of them. An extra 1/8 turn beyond where the crack of light disappears is a good idea.

Below is an exaggerated drawing showing the effects of a full length sizing die on the shoulder and neck lengths during sizing.

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Old May 9, 2013, 12:07 AM   #25
Bart B.
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Unclenick, your artwork is priceless. And very well layed out showing exactly what happens.

My only comment is that folks should not turn dies in presses more than 1/16th turn at a time. That'll move their height about .0045" which, as I think, is the most one should change die height to get the resized case headspace where it should be for the chamber it came out of. A 1/4 turn moves the die about .018". I don't want folks to end up with their resized cases' headspace being 5 to 6 thousandths too short.

And I think it's quite possible to have a crack of light between a shell holder and the bottom of a full length sizing die when its set in the press to set fired case shoulders back a couple thousandths; which is about right for all bottleneck cases. All of my six RCBS .308 Win. dies have that gap between their bottoms and the shellholder sizing fired cases that way for SAAMI spec chambers. This aside, if the die's headspace (shoulder to a touching shellholder) is at its long end of specs, the gap between shell holder and die bottom may well be extremely tiny and sometimes there's none.

Show 'em your die labels for different amouts of die height changes. The .002" and .004" ones are priceless and eliminates guessing on how much the die height's changed.
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