Headspace/sizing problem

You say you are using a comparator. Do you mean a caliper? The dimension you are giving is case length if the original length is correct. Headspace is measured to a datum line on the shoulder on bottleneck cartridges. What you need is the tooling to measure from the base to this datum line. Unless your die is severely defective it is unlikely that the shoulder is being pushed back below specs. Too short case length is not an issue. Too short of headspace is. You need to do a bit more research to find out what is going on. Just basing this on the info you have given.

Follow instructions.
I blacken a case with magic marker and adjust the sizing down until it just contacts the shoulder. I then check if it chambers in the gun. Once it chambers, then I turn the die down maybe ¼ turn just to be sure that the cases all chamber and lock it down.
When you go to neck size, note that you will STILL have to full length size after a few loadings and you'll need to check case length AFTER sizing and trim as needed--do not exceed max case length.

noylj said:

Follow instructions.
I blacken a case with magic marker and adjust the sizing down until it just contacts the shoulder. I then check if it chambers in the gun. Once it chambers, then I turn the die down maybe ¼ turn just to be sure that the cases all chamber and lock it down.

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If you adjust the die down in small increments until it just chambers, then theoretically your case shoulder is set back to just at or under the headspace of your chamber. That is just what I do and exactly where I want to be.

If you then turn the die down another quarter turn, you've set the shoulder back by eighteen thousanths. That's a lot! Setting the shoulder back that much is a recipe for case head separation.

Each 5° turn of the die is almost exactly one thousanth. I use a sharpie to put a mark on the die body and press and use a compass to eyeball how much I'm turning.

Vettepilot555 said:

it bumped my shoulders back by .020". Why?

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Defective die/Wrong die OR shell holder. Shell holder should have a deck height of .125" +/- .001"

Vettepilot555 said:

If I fired the brass in question, at 2.030", it would have to grow by .018" to fill the headspace of my gun. Would this be safe? Would it weaken the brass such that further loading might be dangerous?

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SAAMI Tolerances have a maximum of .013" Head to datum.

Make sure the tool is being used correctly, to get your measurements. Sorry. https://saami.org

Possible case head separations on firing. I had 223 brass separate with .014" shoulder set back.
I traced the problem to the Dillon shell plate. Each station gave a different head to datum reading.

There are some methods to fire form brass that may help?? 1 bullet jammed into rifling. 2. Anneal the brass before firing. 3. Use light oil/ lube on case so it doesnt grap the chamber walls on firing. I have not done any of these.

Reloads would be best fired in a Rem 700 and not a Savage/Mauser type action, Imo, if it was my brass. Less gas leakage and hot brass flying around. What make, model is your 30-06?

I would sell as scrap. Not worth doing bodily harm to body or eyes.

Vettepilot555 said:

But! What about this brass? Is it ruined? If fired, it will have a headspace of about .018". Too much to be safe? (If I do shoot it, I will anneal it before finishing loading them.) Also, I had read that the Lee full length sizer die was made to do a minimal sizing, so what happened here?

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Your cases are not ruined. If the rifle you plan to shoot it in has a claw extractor your chances of having the ammunition fire is good. First of all, before attempting to reload these cases, trim them. If the case neck sticks in the throat you will experience over pressure conditions. After priming, charging, seating the bullet, after all that, lubricate your loaded rounds and fire them lubricated.

With a dry case in a dry chamber the front of the case will adhere to the front of the chamber, and the case sides will be stretched as the case head moves to the bolt face. Since you set the shoulder excessively back, it is likely that the case will separate on the first firing. However, if you break this friction between case and chamber with a lubricant, then the case slides to the bolt face, the shoulders fold out, and the case is stress free and perfectly fireformed to the chamber.

I do this all the time.










I does not take much lube to get the benefit. If you don't have a claw extractor on your rifle you may have misfires because with a short case, the primer is a great distance from the firing pin.

The shooting community has largely forgotten the vast number of weapons that used greased or oiled ammunition. There were a number of machine guns fielded with oilers on top, not because they were delayed blowback mechanisms, but because manufacturing tolerances of the era could not hold headspace measurements on replacement barrels.

And then there were the delayed blowback mechanisms that used oiled or greased ammunition. This phase of firearm history is almost totally forgotten by the shooting community, in fact the leaders of the community have been denial about these mechanisms for decades.



The Oerlikon, and variants, were the most produced machine cannon in WW2, used by the Germans, Japanese, English, and this one is bolted to the deck of the USS Alabama



this is how the mechanism worked:



and this is why you kept your ammunition well greased

Having the decimal in the right place makes a huge difference. Can keep one from destroying a gun. Wrong information gets you the wrong reply. If you feel you must use the brass I would fire form it by using a light load. Seat the bullet out to touch the rifling and let er rip. I never anneal brass. Shoot quite a bit, but, not enough for that. However if you have a good annealing technique that will help with the process. I personally never use brass that I don't know what it was fired in.

It is very surprising that the factory die set the shoulder back that far. I agree with others that some investigation needs to be done.

Vettepilot555 said:

Using my comparator, new rounds measure 2.44", and brass fired in my rifle measure 2.48". This used brass measured around 2.49 to 2.50 before I sized it. So imagine my surprise and consternation when I measured the brass after full length resizing to find it 2.30"!!
<...>
Also remains the question of whether you all think that this brass would be safe to shoot once annealed. Once again, using my case comparator, which measures from shell base to the shoulder datum, new unfired brass measures 2.044". Brass fired in my gun measures 2.048". This brass I just sized with the Lee full length sizing die measures 2.030".

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Whew! I was wondering what was going on with your first set of measurements... 2.44" is much different from 2.044"! The difference between 2.44" and 2.30" is 140/1000th of an inch. That is MUCH larger than the difference between 2.044" and 2.030" which is only 14/1000th of an inch.

Also, since you are taking measurements of the case shoulder, I believe you are actually referring to the Hornady Lock-N-Load "Headspace Gauge" and NOT the "Bullet Comparator" which measures the distance to the ogive of the seated bullet.

I found a pic of the SAAMI spec for 30-06. The diagram suggests that the distance from the head to the area of the shoulder where the diameter is 0.375" (proper Headspace Gauge collar for 30/06) should be 2.0526".

All your measurements are smaller than the case specs above. This is good. For this measurement I'd think you want to error on the side of smaller so the case fits into the chamber. Also note that the headspace distance is NOT a reference measurement (indicated by triangle).


It sounds like your Lee FL die is sizing the cases a bit smaller than factory (off-the-shelf) ammo or your rifle's chamber, but not overly so. I expect a FL sizing dies to set the case dimensions smaller than SAAMI spec so it will fit into ANY chamber that is at EXACTLY SAAMI spec. Once you fire the case it should fire form to your chamber.

I would have no problem using your resized cases.

I would not recommend shooting it as . Minimum length to the datum line is 2.045. That still results in very large headspace. You might separate or crack a case. You will stretch the brass excessively ahead of the web leading to issues with further loading. If you had a rifle with a chamber ..015 to long it would swallow a field gauge. This would indicate the firearm is unsafe to fire. Your chamber is fine ,but the very short brass , causes the same situation.

What Walkalong said. I'd only add that you might also remove the ejector from the bolt so it's not applying forward pressure.

Something else you may want to consider is the gauge you are using. I am assuming you are using a Hornady Lock-N-Load® Headspace Comparator & Anvil Base Kit which has a few caveats to it. While the gauge does its intended use well when used with the directions problems can arise when we begin bringing SAAMI case dimensions into things. I can give you a pictorial of what goes wrong.

The below examples use a 308 Winchester as an example. We start out with the gauge:


The three gizmos on the bottom of the image are actual headspace gauges. We assemble the gauge with out caliper:


We zero the caliper:


Now we will see where things go wrong. Using a .308 Winchester actual headspace gauge we will measure the gauge. Just as a side note before I retired I ran all of my headspace gauges on an optical comparator and also a Zeiss CMM (Coordinate Measuring Machine) and the gauges are within a few millionths of true. So for our purposes they are as good as gold. My .308 Winchester gauge was a standard Go Gauge measuring 1.630".




The problem is that the collets included do not have sharp well defined corner breaks but rather have a slight bevel so where the case shoulder contact is made is not exactly where the datum reference in the cartridge drawing actually is. In this example the reading is 0.006" low.

Normally if I fire a bottle neck case like a 30-06 Springfield in my rifle and then measure the fired case I can figure that what I measure case head to shoulder datum is about 0.001" short of my actual chamber headspace, not a very exacting science but normally close enough. Unless when using the above pictured gauge the end user has a true accurate headspace gauge (not a case gauge but a chamber headspace gauge) they have no clue what the actual numbers really are. The idea behind the gauge is we can measure a case or loaded cartridge, fire the cartridge and then resize the case to be about 0.002" or 0.003" less than where we started. The gauge works just fine in that application but when we get beyond using the gauge as a comparator and comparing to actual SAAMI drawing numbers it can lead to questions and problems. My own observation of these gauges is they generally read low and generally 0.004" to 0.008" low.

Doing the same as above, using a 0.375" collet on a true 30-06 Springfield Go gauge I measure 2.044" and the actual is 2.049" so there we have a -0.005" error or in SAMMI spec the difference between a Go or NoGo chamber. Again, the gauge does as intended but keep in mind do not compare the gauge numbers to SAAMI specification numbers.

Ron

Ron

Reloadron, that is a great post ! What you described so well is why I tell folks it is a comparator only. To give Hornady credit I believe that is what they call it. You illustrate the difference very well.

-Jeff

Bartojc said:

Reloadron, that is a great post ! What you described so well is why I tell folks it is a comparator only. To give Hornady credit I believe that is what they call it. You illustrate the difference very well.

-Jeff

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Hornady does appropriately call it a headspace comparator. But, unfortunately, some sellers call it everything from headspace comparator to headspace gauge to headspace gauge comparator, leading some folks to think that it actually measures headspace.

Yeah, naming conventions can be a little tricky.

Ron

I put a .010 feeler gauge under the shell holder or on top than screw the Die down to touch. From there I can adjust headspace in .001 increments.
Any type of a gizzy (comparator) can be used to measure headspace such as a spent 9 mm cartridge or a 30.06 cartridge.
J

Vettepilot555 said:

I've decided what I am going to do. I am going to fireform the cases with 10 grains of Unique. I have experience in this, as I made my brother in law a bunch of cool brass cases for his .410 shotgun out of some 9.3 x 74r brass.

Do you all think I should fill the cases with crushed walnut shells or corn cob media on top of the Unique, or just load the Unique, a projectile, and go for it?

Also, one last question. I used Lee's case lube this time, and looking closely into the die with a bright light, I can see bits of clumped lube. Do you think buildup of wax in the die could have caused the problem??

Vettepilot

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Using a modest charge of your normal powder stuff a 100% cotton ball in the neck instead of a projectile then pop them off in the garage or backyard

Vettepilot555 said:

Do you think buildup of wax in the die could have caused the problem??

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To much RCBS lube forms lube dents. Not an even sizing of the shoulder.

Lee wax has been a problem when lubing the inside of the case neck with a Q-Tip and seating boatail bullets. The blob of extra lube had a hydraulic effect , expanding the case neck in 1 area.

Check the vent hole in the fl die. It needs to be open. If pluged, may get compression when sizing??

Fire forming with light loads- I found Hodgdon Youth Loads would make the head to datum shorter after firing my 30-06. Takes a near maximum load to fire form brass. Imo.