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Old March 9, 2013, 09:33 PM   #1
Colorado Redneck
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Full Length sizing and headspace

Resizing 22-250 brass today. Neck sizing had been giving me fits as the bolt would close really hard (not good) so I had worked through that issue by full length resizing. Then reading threads here in TFL about headspace issues I figured I should follow often stated advice to "bump the shoulder back" 0.001 so the brass is snug in the chamber but not crushed against the shoulder. Expermimenting around and measuring lots of fired brass and trying the resized brass in the rifle, I had developed a max. length for the Hornady Headspace gage reading that would work.

So today, I set up the FL die and lubed up the tumbled cases and ran them through. I checked several along the way, and found that some cases were not coming out of the die wiith the proper headspace---they were longer by .001 or more. And some were coming out .003-4 shorter than I wanted. I was beginning to think about pulling more of my few remainin hairs out of my old bald head at this point.

To cut to the chase, there were two observations:
1. The brass that was coming out short was all Remington R-P brass. The rest was all Winchester brass.

2. The reason (as near as I can tell at this point---more unexpected results will probably crop up in the future) for the longer brass was not enough case lube, and the cases were getting re-stretched as the die was being raised off the case. I rolled the cases in the RCBS lube realllly good and ran them back thru the sizer and they all came out exactly where I wanted them. Evidently the R-P brass is thicker or less malleable than the Winchester brass.

The number of variables seems endless for what I thought was a simple process. Dang. Ignorance is really tempting. Anyway, maybe this can save some poor hapless soul from tearing their hair out over the same thing.
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Old March 9, 2013, 09:59 PM   #2
Nathan
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Case lube and the difference in brass are your issues. I think more lube, especially some in the case mouth, will get you ~+/-0.002. My mixed head stamp 223 with Hornady Unique lube applied by pad and neck dipped in tub got me that level of consistency.

In my experience, a reasonably stiff action will close well with fired +0.002, but a weak action will be ejecting brass which is ~+0.005 to the real chamber headspace due to flex, etc. if that is your fired case size, you have to FL size to -0.005" just to get to nominal! I probably exaggerated a bit, but that is just an example.

A shoulder bump die might be best, but once you are bumping the shoulder, might as well use the FL die. Do get a RO gage, so you can minimize runout in die setup.
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Old March 9, 2013, 11:39 PM   #3
Colorado Redneck
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Nathan---great comments. Yeah, I had been brushing the inside of the case mouth with a bit of lube, but omitted that step today since the brass was really shiney and clean from tumbling for several hours. Evidently there is no end to the kind of mindless decisions that can change things. So that was another thing that probably made a difference the second time thru the sizing die. Thanks for mentioning that.

What is really amazing is how accurate and consistent this rifle is, in spite of me.
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Old March 10, 2013, 10:40 AM   #4
PA-Joe
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Your observations are correct. Rem brass is thicker and is sized for a tighter chamber. As a general rule it also has a shorter COL and most do not have to be trimmed until the second or third reloading.
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Old March 10, 2013, 10:50 AM   #5
g.willikers
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As you have discovered, reloading for rifles is much more difficult than for pistol.
Especially if the expected results are to be at least as good as common factory rounds.
To add to the aggravation, it often doesn't even save all that much money.
It takes motivation to reload for rifles.
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Old March 10, 2013, 12:23 PM   #6
Bart B.
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Colorado Redneck, if best accuracy is your objective, sized cases should have their shoulders set back so there's no binding/resistance closing the bolt on one whatsoever. "Snug fits" are bad 'cause they still cause the bolt to close at different positions when closed on such cases. Which is why the popular thing to do is set the fired case shoulder back 1 to 2 thousandths. When benchresters neck sizing their cases started getting snug fits of their cases when chambered, that was a sign that their headspace had grown too much and accuracy was going to get worse. Most of them finally learned to full length size their cases all the time but not set shoulders back more than about .001".

Redding's competition shell holders come in .002" steps above the standard height of .125". One of them should work for your rifle's fired cases when the shell holder just bumps slightly against the bottom of the die when it's set to bump the fired case shoulder back about .002". With this setup, your spread across case headspace may well be less than .001".
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Old March 10, 2013, 09:46 PM   #7
Colorado Redneck
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Bart--Thanks for the suggestion concerning Redding shell holders. The way this situation evolved had to do with difficult bolt closing. I had loaded most of the cases two or three times (at least) and had been neck sizing. I posted a question here and in that thread full Length sizing was suggested, rather than neck sizing. That fixed the problem, but there were a couple of suggestions about "bumping the shoulder back" a small amount. So one thing led to another, and it continues to evolve.

I have to say this rifle is one accurate shooter. So that is really not much of an issue---right now. Probably as I continue to try to improve my loading technique I will figure out a way to undo that.

If accuracy were an issue, then the Redding comp shell holder set would be a great improvement. I have a 222 that is persnickety as heck about headspace. So the comp shell holder set might be a solution for that particular gun.

Thanks again for the great comments!
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Old March 11, 2013, 03:55 AM   #8
Nathan
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Quote:
With this setup, your spread across case headspace may well be less than .001".
How will a shell holder do that? I assumed all my variation came from case hardness and evenness or lubrication.
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Old March 11, 2013, 07:23 AM   #9
Bart B.
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Nathan, shellholder height determines how far the fired case gets pushed into the sizing die when the die touches it when resizing fired cases. If two shellholder heights are used, for example .125" and .131", and they both press against the bottom of the die at the top of the ram's stroke, the .131" one will end up having the full length sized case shoulder further from its case head than the .125" one would have made. The .131" one has its bottom .006" further down from its top than the .125" one. The distance from the die's bottom to its shoulder stays the same. (I call this dimension from the shellholder bottom to the die's shoulder "die headspace.")

If the shellholder doesn't stop against the die's bottom but instead there's clearance, depending on the lubricity of the case lube along with how much is on the cases and how much up-down spring the press has, the size case headspace (head to shoulder dimension) will vary. It can easily have a .004" spread.

Some folks have pushed a fired case up into a full length sizing die, left it there then looked at the gap between the shellholder and die bottom. Watching it for a while they've noticed it getting smaller as the springback in the press frame slowly pulls the die down a few thousandths on the case. How long the press ram's held the case up into the die determines how much springback the press frame will further set the case shoulder back.
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Last edited by Bart B.; March 11, 2013 at 07:35 AM.
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Old March 12, 2013, 10:33 AM   #10
F. Guffey
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Resistance to being sized, two ways to determine if the case won or the press won. There are very few that can use the top of the press to determine if the press continues to win over the cases resistance to being sized. That leaves the gap between the bottom of the die and top of the shell holder. A most simple solution is the feeler gage, the feeler gage is a standard, it is a transfer, and it is a verifying tool, meaning: verifying tool explained.

There was a reloader that claimed he used a flash light to gage the gap, my opinion? The only gaging that went on with the light was a wild guestimate, the only information gained was: He knew the die was not making it to the shell holder.

And now we have Bart B. and:

“Some folks have pushed a fired case up into a full length sizing die, left it there then looked at the gap between the shell holder and die bottom. Watching it for a while they've noticed it getting smaller as the spring back in the press frame slowly pulls the die down a few thousandths on the case. How long the press ram's held the case up into the die determines how much springbuck the press frame will further set the case shoulder back”

Jump-back, spring-back or snap back: It is Unclenicks story and I am sticking to it. Simple, just raise the ram, stop, lower the ram then raise the ram again, careful not to lower the ram far enough to pull the neck sizer plug through the neck the first time the ram is lowered. Then there is that part where the case snaps back, try this, purchase a forming die, if a reloader does not have a forming die I suggest one of two or both, the 308 W forming die and the 243 W forming die. Back to snap-back and or jump-back, Form a 308 W case using a 30/06 case, pushing the 30/06 case through the 308 W forming die creates pressure on the case below the neck of the die, as the cases is forced the die .380”+ of the case will protrude above the die, the procedure for trimming requires a hack saw and then a file to complete the trimming process.

Back to Snap, jump or spring back. after trimming do not lower the ram, simply watch and add another sense to the test, feel, if the case continues to be pushed through the die after the ram is raised the case will began to protrude through the top of the forming die, look first then feel, if the case spring back, jumps back or has snap back it will began to protrude, back to the story that I am ‘sticking with it’, lower the ram then raise the ram again, then take the file and trim again because there will be an additional .010 +/- a few. Cases are pushed into the die, means nothing to anyone but if the case was pulled through the die the case would not wad up on the shell holder side.

If a reloader wants to know if the case refuses to be pushed into the die get a feeler gage, measure the gap between the bottom of the die and top of the shell holder in thousandths, if they want to know if the pressure on the bottom of the case is relaxing place a feeler gage between the shell holder and bottom of the die after raising the ram and sit there, eventually the shell holder will get closer to the die and prevent removal of the feeler gage (if the resistance to sizing is not greater than the press, die and shell holders ability to overcome resistance to sizing).

Test in the old days measured such matters, I do not believe it will happen again in reloading until someone googles for an answer, or has an An epiphany, something like “OH LOOK! See what I just discovered....”


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Old March 12, 2013, 10:47 AM   #11
F. Guffey
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Redding competition shell holders: Are expensive, $40.00 a set, I paid $5.00 for a #6 set, three are off by .001” each, not a problem, anything a Redding Competition shell holder can do I can duplicate with a feeler gage, then after duplicating the effect the shell holders have on sizing I can determine it there is an advantage as in ‘Do I really need the Redding shell holders?’ If the reloader is having trouble closing the bolt on a sized case the Redding shell holders will become something that is nice to have but not necessary. The purpose of the Redding shell holders is to add to the length of the case between the shoulder of the case and case head, the Redding shell holders does nothing for restoring a case to minimum length/full length sizing.

Then we are back to firing to form then neck sizing 5 times then starting all over by full length sizing, every time a case is fired it increases in resistance to sizing, meaning when the case increases in resistance to being sized the press must be adjusted to increase its ability to overcome the cases resistance to being sized, remember, in the perfect world the perfect case to size/form is a new case, after that resistance to sizing is progressive.

Back to the feeler gage, I use a feeler gage to determine the cases ability to resist sizing. Difference? I know the length of the chamber first, It is not necessary for me to fire first.

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