Lake City headstamp

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I feel dumb for having to ask this but....

On say 556x45 lake city brass, the number i.e "14" or "15" is the year right? If so, does anyone really see much difference between lots/years?

I ask because I have a precision load and I need 50 more pieces. The ones I already have are "14" and the 60 I have to add and shoot first are factory loaded and stamped"15"

I have noticed plenty of variations within lots of brass. My best example is my .338 LM lapua brass, I have gone through 3 batches of 100 with some lasting 7 loads, some up to 9 loads from the same exact batch and the weight of each case is different. But there was absolutely no difference in performance to my eye between cases lasting 7 loads or 9, only that the necks split earlier some than others.

Anyway thanks in advance.
 
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Heck, there's differences within the same year. Lol.

I don't even look at date anymore. I just sort all of them by case capacity anymore.


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The dates let you know what year they were manufactured, other than that, it don't mean nothing to a reloader. LC is good brass, no matter what year .
 
Heck, there's differences within the same year. Lol.

I don't even look at date anymore. I just sort all of them by case capacity anymore.
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That sums it up well. If I am looking to load some accurate ammunition I will sort by year and then weigh the cases or measure volume if I am really serious. Even with all of that attention to detail, honestly, I only have two of several .223 Remington rifles where the difference is noticeable. One a bolt gun and the other a 24" match barreled AR. The other rifles see no difference and shoot as well as they are going to shoot.

Ron
 
It can be more valuable to sort by load history. If a set of cases have the same headstamp and are the same age, they will usually be made from the same brass alloy, even if they came off different tooling sets. If each load cycle then is loaded using the same dies and components for that cycle and are all fired in the same chamber for that cycle, then work hardening of the necks will tend to match and give average bullet pull that tends to match. This matters more as the cases age and get further from their last neck annealing.

Sorting by weight can help you identify which tooling set the cases came from and that usually corresponds well to capacity. There often is, however, some overlap. The illustration below is how one set of Winchester bulk brass I got weighed out. I lined the actual cases up above their weight on a scale I made on a large piece of poster layout graph paper (not shown; Walmart had it). The four peaks indicate four sets of tooling were involved in making this lot of cases. You can see the bell curve shape of each tool set's output and can see the tails of the bell curves overlapping, especially between tool sets 2 and 3.

Brass%20Distribution_zpspyb8k6uh.gif
 
On say 556x45 lake city brass, the number i.e "14" or "15" is the year right? If so, does anyone really see much difference between lots/years?
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Sorting brass: I believe it is a little short sighted for a reloader to short brass without a plan. A reloader that sorts brass will sort brass for the rest of there reloading life. I keep cases together, with different head stamps a reloader should not have a problem sorting cases after tumbling. I have tumbled as many as 300 30/06 cases at one time; to get the cases back in the same box al I have been required to do is sort by head stamp.

And then there is the assumption: Reloaders assume cases that weight the same are the same and they believe military cases are thicker because they are heavier: AGAIN, that assumption is only half truth because some military case heads are thinner but heavier than commercial brass. If that is true military case body has to be thicker if the case head is thinner. I have military cases with .200" thick case heads but heavier than R-P cases with case heads that are .260" thick, while assuming I assume the R-P case body is thinner than the military case with the thin case head.

And then I never wonder but I understand the length of the powder column has to be longer and thinner than the R-P powder column. That would leave the power column in the R-P case shorter but larger in diameter.

I do believe the R-P cases is safer than the thin military case with the thin case head. I sort cases, I like keeping my cases together and I am the fan of being able to sort cases after tumbling.

F. Guffey
 
Thanks for the last two posts by Mr Guffy and Nick.

I have Always sorted by times fired when making a mixed headstamp bulk plinking batch, they have all been loaded the same number of times. There is certainly a noticeable difference in neck tension when seating bullets between say 2nd firing and 7th firing.

In my bolt guns I always keep everything thing the same , age, headstamp, trim, gun they are fired in etc.

I guess, to be most specific, what I was getting at is this: do the alloys from different years, maybe even consecutive years matter. I will be sorting by volume but can't obviously do anything about the year the headstamp is from.
It sounds like it CAN matter but that case volume and times fired from the same brass make (lake city in this case) is much more important than the year they were made?
 
I would assume that no two lots of brass are absolutely identical alloys down to the last part per million, but most of the time a manufacturer will spec the same general alloy and the properties won't be wildly different. But not always. This article shows Lapua using both 75:25 brass and the less expensive Muntz metal in 2010. I would expect that to produce different bullet pulls, at least after a few reload cycles. Keeping the brass separated by origin (in the case of that Lapua, brown box vs. blue box brass) is all most people can do about it. The other way to tell is to set up a means of measuring bullet seating force. I have a special gauge for this that RSI used to make and says they will replace at some point. You can also rig strain gauges to a press to measure it, but you need some technical knowledge to do that.
 
Unclenick mentioned:
You can also rig strain gauges to a press to measure it, but you need some technical knowledge to do that.
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No, I need access to the machine shop I had access to before I went and retired. Damn, I miss that perk, not the work but a few of the perks. I have wanted to build a stand onto a single stage press to measure tension when pulling a bullet and compression when seating a bullet. :)

Ron
 
Well I think in summary, it is safe to say that, barring some significant change in tool usage or alloy composition, there is very little difference from year to year or lot to lot.
Essentially, there is/or may be more within lot variation than the average from lot to lot. So, all I can really do is check volume, weight, and times fired.

The fact that one group was made in '14 and another in '15 is only relevant to the extent of what I said above.

So in the end I will ignore the year.

Thanks again
 
reloadron said:
No, I need access to the machine shop I had access to before I went and retired. Damn, I miss that perk, not the work but a few of the perks. I have wanted to build a stand onto a single stage press to measure tension when pulling a bullet and compression when seating a bullet.
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Strain gauges glued to the press frame will turn it into a load cell that will measure both for you. The tricks are picking the best spot and getting valid calibration.
 
Originally Posted by reloadron
No, I need access to the machine shop I had access to before I went and retired. Damn, I miss that perk, not the work but a few of the perks. I have wanted to build a stand onto a single stage press to measure tension when pulling a bullet and compression when seating a bullet.
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A tool is available for measuring the effort required to seat a bullet. Seating press is hydraulic with a pressure gage. As I have said from the big inning measuring neck tension can not be measured with a neck tension gage because it does not exist. Bench resters were excited when the hydraulic press was introduced. The gage on the press measures pounds, not tensions and the instructions do not include a conversion from pounds to tensions.

After the tool was out and in use I thought users were going to require therapy; users thought the amount of effort to seat a bullet was going to be uniform. That did not happen; there was a 25 pound spread. I have always said the best technique for seating bullets was the alignment between the bullet and neck.

I have been able to seat and measure effort from the beginning. A bath room scale and an in-line seating die works. I have old Lyman in-line seating dies and old Lee dies and I have Herter dies, my favorite seating die is the one with the hole in the side. And then there are RCBS seating die like competition and Gold medal.

And then one day I made a bullet seater, no die body, just a seater.

F. Guffey
 
Unclenick:
Strain gauges glued to the press frame will turn it into a load cell that will measure both for you. The tricks are picking the best spot and getting valid calibration.
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Thanks. I have, somewhere around here, some strain gauges. Matter of fact quite a few. I also have an old Lee O Press I don't use. Guess I could dig out some parts and build a bridge. Been some years since I prepped a surface for a strain gauge but I have done it. I also have some old displays to read the gauge and provide excitation. I did have a S beam 100lb load cell somewhere. Just wish I had that machine shop so marrying the parts would be easier. While I was never a ME type I was fortunate to work with some great Mechanical Engineering types. :) I miss those guys.

Thanks for giving me some more thoughts.

Ron
 
http://www.xxicsi.com/hydro-bullet-seater.html

John seats bullets into two cases and has a spread. He suggest sorting because of the spread and then there is that gage, I would want my money back because I am the fan of verifying and gages that zero, and then there is the gage, no tension; just pounds.

I did not have enough curiosity about the price but I would think the press would cost close to $250.00.

F. Guffey
 
Anyone that can drill a straight hole and cut grooves in a shaft can make a jack and determine the amount of pressure with an inline gage. Had I designed a press to determine the amount of effort for seating a bullet I would not have designed it like the 21 Century tool.

F. Guffey
 
F. Guffy:
A tool is available for measuring the effort required to seat a bullet. Seating press is hydraulic with a pressure gage. As I have said from the big inning measuring neck tension can not be measured with a neck tension gage because it does not exist. Bench resters were excited when the hydraulic press was introduced. The gage on the press measures pounds, not tensions and the instructions do not include a conversion from pounds to tensions.

After the tool was out and in use I thought users were going to require therapy; users thought the amount of effort to seat a bullet was going to be uniform. That did not happen; there was a 25 pound spread. I have always said the best technique for seating bullets was the alignment between the bullet and neck.

I have been able to seat and measure effort from the beginning. A bath room scale and an in-line seating die works. I have old Lyman in-line seating dies and old Lee dies and I have Herter dies, my favorite seating die is the one with the hole in the side. And then there are RCBS seating die like competition and Gold medal.

And then one day I made a bullet seater, no die body, just a seater.

F. Guffey
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I agree with a hydraulic arbor press knowing the force is easy if we know the cylinder diameter and the pressure applied. The cylinder pressure x the Cylinder Diameter = Force. If we use sq. in X psi we get the force in pounds. I worked with a few dead weight test units over the years and force test systems.

I really don't care for what we seem to call neck tension even though I use the term. I like to measure the neck pull and more important having uniform pull over a complete set of hand loaded rounds. Starting with uniform brass right down to neck thickness.

Anyway, I am dragging this poor thread way off topic and really don't want to do that. Rather than hydraulics to seat or pull (push/pull) a bullet I would rather run with a force transducer as Unclenick mentioned. I have several and an old Lee O press I would like to experiment with.

Thanks
Ron
 
I had rather use bullet hold because I can measure bullet hold in pounds, I did not invent nor did I discover the concept. Reloaders are in·fat·u·ated with neck tension with no way to measure it.

I have tension gages, I have deflection gages, I do not have a gage that is calibrated to tensions nor do I have a conversion table that goes from tensions to deflections or tensions to pounds.

F. Guffey
 
Well then, it seems that the best "rule of thumb" is to keep all else equal, and ensure that all cases are trimmed and fired the same number of times.

It wont be nearly as exact as testing using a force gauge, but it will give you the best consistency you can hope to obtain.

The issue I see with testing with respect to pulled force though is that it would be necessary on every case to be useful, and based on the methods described below, how can you test the pull force of each case without changing that force. In other words, if we are drilling down to the nth decimal, once you seat a bullet you stretch the neck to a degree. If you then pull it, it will need re-sized but likely will never return to that tension after being stretched and sized again. So your initial reading is void immediately following the test.

So essentially all you could do is use a seating force gauge as mentioned below as a proxy for tension and sort accordingly. This point however likely becomes moot if you have not already sorted for capacity. What I would like to know is: what is the relationship between force and accuracy? Is 10 ftlbs insignificant? Or is it enough to open a 1/4 inch group to 3/4 inch? In the end that is the question that matters most.
 
So essentially all you could do is use a seating force gauge as mentioned below as a proxy for tension and sort accordingly. This point however likely becomes moot if you have not already sorted for capacity. What I would like to know is: what is the relationship between force and accuracy? Is 10 ftlbs insignificant? Or is it enough to open a 1/4 inch group to 3/4 inch? In the end that is the question that matters most.
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I noticed the amount of force was different in the demonstration by Century 21; John? suggested the two cases be separated because the bullet hold was more on one than the other. I could ask; why? There must be many reloaders that believe the tighter the neck will hold onto the bullet longer than a neck with less bullet hold. I have always ask how 'longer' is measured? There must be a unit of measure for longer.

I am the fan of bullet hold, I want all the bullet hold I can get. My bullet hold measures 45 pounds +/- a few on bottle neck cases.

F. Guffey
 
F. Guffy

I had rather use bullet hold because I can measure bullet hold in pounds, I did not invent nor did I discover the concept. Reloaders are in·fat·u·ated with neck tension with no way to measure it.

I have tension gages, I have deflection gages, I do not have a gage that is calibrated to tensions nor do I have a conversion table that goes from tensions to deflections or tensions to pounds.

F. Guffey
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The above is where we seem to have a problem. For reasons I will never understand you seem to have this view that all reloaders should be lumped together excluding yourself. I have been reloading for a few years, maybe around forty-four and shooting a little longer. I guess I am a reloader. I do not have an infatuation with anything and have no idea why the call it "neck tension" anymore that I have a clue why the term headspace is often applied to cartridges. I can tell you with assurance I was not behind those naming conventions and please stop lumping all reloaders together with the exception of yourself unless of course you are not a reloader.

Here allow me to fix this for you:
Reloaders are in·fat·u·ated with neck tension with no way to measure it.
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Should read:
There are some within the reloading community who refer to "neck tension" yet do not seem to have a way to measure it.
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See how easy that was and I did not make those who reload an all inclusive group.

Now back on target. I agree as to bullet pull which has a defined unit of measure. We can measure it as pounds of force (lbf) if we choose the English Unit of force. Even with that said, regardless of how we derive the measurement, the end result will be a curve similar to a chamber pressure curve. There will be the breakaway force (as the bullet breaks free) and the force required to slowly drag the bullet from the case mouth.

Finally I wonder if with added effort we could possibly drag this thread any further off topic? I want to pursue the idea of measuring the pull required to drag a seated bullet out of a case neck. Rather than pursue the hydraulic pressure method I will go with the use of a force transducer configuration as Unclenick mentioned, less messy and I am comfortable with it.

<EDIT>
One more thing as someone who has worked with gauges for a good portion of his life the word is gauge and not gage;
What does gage mean? Gage is defined as something given as security against an obligation; a pledge.

Bring a sufficient gage or don’t bother coming along.
His car acted as a gage for the bank.

What does gauge mean? Gauge, as a noun, is defined as a standard dimension, quantity, or capacity.

This looks like 30 gauge steel.
We took our 12-gauge shotgun hunting.
A gauge is also a type of measurement tool, such as a tire gauge, a pressure gauge, a fuel gauge, an oil gauge, etc.

The air gauge says your tire pressure is 35 PSI.

If you plan to use the word at least try and get the correct use and spelling.
</EDIT>

Ron
 
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