223 vs 5.56

I apologize for any misunderstanding,

You misunderstood my last response.

I was willing to put in the time and effort to provide serious and thoughtful responses as long as there was some progress in a constructive direction. When a discussion devolves to the point that one participant responds to a 500 word post by asking a ridiculous question like "Can you quantify "most likely"?", it's abundantly obvious that the discussion has ceased to be productive and has become waste of time for all involved.
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My question is most definitely not "ridiculous."

What has become completely obvious is that you cannot quantify your assertions. That is ok, I can't quantify anything here either since I don't have access to the data necessary to answer those questions.

In any endeavor you have "known unknowns" and "unknown unknowns." We've been talking about the "known unknowns" for quite some time now, and with access to good data it wouldn't be too hard to weight the known risks for probabilities for events. As an engineer I'm sure you are familiar with modeling consequences/systems in some fashion.

You answered with some certainty that the chamber was the "most likely the probable cause." I want to understand why you can be so certain because you must clearly know something that I don't.

Because it all comes back to the same data points that I have available, that Patrick Sweeney mentioned, that it wasn't a chamber mismatch under normal circumstances popping primers as the observed pressure increases weren't dramatic.

So, how can you be so certain, and yet not be able to quantify that certainty? In the engineering world, anything that can be quantified can be optimized, so wouldn't it be nice to put some numbers down?

I'm not an engineer, but my background is in science. One of the things considered good science is to not listen to "expert testimony" without looking at the data from that expert. Science is littered with experts who were wrong. And getting back to Ocham's razor, lets counter that bit of wisdom with this: For every complex problem there is an answer that is clear, simple, and wrong.

Jimro
 
All anyone needs to clearly and easily see the difference between 5.56 and 223 is a chronograph...the 5.56 will outrun the 223 by 150-200 fps with any and all bullet weights...

5.56 is most certainly loaded hotter...it can safely be said that 5.56 is at least 223 +P...and some 5.56 would qualify for +P+ (Black Hills 5.56 mk262 for example)

Modern 223 bolt actions will be safe with 5.56....its semi autos that you have to be careful with.

Chrono results...

Hornady Custom 223 75 grain bullet...2,528 fps.

Black Hills 5.56 mk262 (75 grain bullet)....2,687 fps.

Both rounds fired from my 16" Sig 516.
 
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Ridgerunner665,

It gets even more interesting when you get into loading 223 for bolt action rifles.

Sierra usually has very sedate load data, but lists 27.3gr of BLC-2, or 25.8gr of H335 under an 80gr SMK as a max load for a Rem600 with 24" 1:8 barrel, 2900 fps in both cases. That's a pretty hefty charge with known temp sensitive powders. But completely safe in a 223 Rem chamber, no popped primers, so I take that as one more indicator that the primers are getting popped during some point in extraction.

I can't prove it, though, which frustrates me.

Jimro
 
BLC-2 doesn't usually generate max pressure, at least not full 5.56 pressure....I've never used H335...but BLC-2 is pretty friendly in the 223.

That said...subjecting small rifle primers and brass to big magnum pressure could be the problem...have you tried CCI 41 primers and NATO brass?

I have not read the entire thread...
 
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Never had a problem, and I've shot 5.56x45 through an NEF handi in .223.

But I'm about to get a custom match-chambered Ruger 77 in .223, and definitely will not be trying it in that one.
 
One first hand problem I have witnessed, was a relative fired a 5.56X45 round through a bolt action savage .223.

The bolt locked up solid and had to be taken to a gunsmith to be disassembled. I'm Not sure of the age of this rifle, but it did not appear to be a new rifle. The ammo was new manufacture, 55 grain, LC brass.

This happened several years ago, I adopted the policy to never fire 5.56 in anything chambered for .223
 
The bolt locked up solid and had to be taken to a gunsmith to be disassembled. I'm Not sure of the age of this rifle, but it did not appear to be a new rifle. The ammo was new manufacture, 55 grain, LC brass.
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Did you happen to note the manufacturer and lot number? Lake City only makes 55gr FMJ for export to our allies, so most 55gr FMJ in LC brass in the US is commercially reloaded ammo, either from once fired brass or from pulled components.

The milspec pressure spec for M193 was originally 53k CUP. That won't lock up a Savage unless something else is out of spec (bad powder, extra long neck, obstructed bore, etc). And lastly, did the gunsmith explain the problem after doing any sort of forensic investigation? Did vibration cause the Savage safety to go into the locked bolt position? Were there overpressure signs on the case upon extraction? Was the primer popped?

This is why "I used this ammo, and this happened" isn't exactly useful in understanding WHAT happened. "Post hoc ergo propter hoc" is a logical fallacy.

Jimro
 
lol I know that's counts but FIRST hand by seing it happen to someone eles It sure is a lot better then
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You don't understand, this was a family member I was with him at the time we traveled to the shooting area together. He fired the round, and could not get the bolt open, we both looked at it and determined we needed a gunsmith to fix it before we broke something.

I am even privy to the gunsmiths root cause analysis which was "excessive pressure"

What more do you want, maybe I could go back in time and try to convince myself to take a video camera with me that day, SHEEZ!
 
Did you happen to note the manufacturer and lot number? Lake City only makes 55gr FMJ for export to our allies, so most 55gr FMJ in LC brass in the US is commercially reloaded ammo, either from once fired brass or from pulled components.
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I must disagree, I have been buying Federal XM193 off and on for years, it's been LC brass for as long as I can remember. I checked my stock, I have some new Federal XM193 in storage going back to LC -11 on the head stamp.

You say this was not enough to lock up a savage action, I must again disagree, as I was present when it did. I did not note the lot number, I suspect it was from a 840 round case of XM193 we purchased together, we just went on the advice of the gunsmith who fixed it. There is no reason to doubt him, as the rifle is fine to this day (with .223 ammo).
 
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You say this was not enough to lock up a savage action, I must again disagree, as I was present when it did. I did not note the lot number, I suspect it was from a 840 round case of XM193 we purchased together, we just went on the advice of the gunsmith who fixed it. There is no reason to doubt him, as the rifle is fine to this day (with .223 ammo).
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Disagree all you want, but realize that you don't know if it was a long neck on the brass that raised pressure or if the powder went bad or if it was anything else.

All you really know is that you had a round lock up the rifle, and it hasn't happened again since you stopped using that lot of ammunition. Those two data points don't tell you that a chamber mismatch is to blame only that a mismatch is a possibility (along with the others mentioned in this thread).

That Savage wouldn't happen to be a Model 25 would it?

Jimro
 
Well, there you go - firsthand report!
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Actually it's the fourth firsthand report on this thread indicating that 5.56 in a .223 chamber results in higher pressure and the third firsthand report noting that the mismatch caused serious issues (popped primers, stuck cases). One of the latter three actually reamed the .223 chamber to 5.56 and found that the problems that had previously existed disappeared, even when using the same ammunition.
All you really know is that you had a round lock up the rifle, and it hasn't happened again since you stopped using that lot of ammunition. Those two data points don't tell you that a chamber mismatch is to blame only that a mismatch is a possibility (along with the others mentioned in this thread).
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While your statements are technically correct, they are taking the idea of scientific skepticism beyond the pale of what is reasonable.

You've essentially decided upon threshold/burden of proof that insures no one will ever satisfy you as to what is causing the problem--UNLESS they choose one of the explanations that you prefer over the mismatch warning.

It would be one thing if you uniformly applied that same level of skepticism, but you don't. You are willing to accept other explanations (even those which are charitably described as pure speculation and/or which don't even conform to the information provided by the sources from which you quote them) as more valid than the chamber/ammo mismatch.

1. We have a number of respected and technically competent authorities ( Remington, Winchester, SAAMI, Hornady among others) who have provided virtually identical warnings and explanations.

2. We have numerous reports from those who have ignored the warnings and encountered exactly the circumstances that the warnings predicted. Several firsthand reports on this thread, in fact.

3. We have one firsthand report from a person who experienced the problem, eliminated the mismatch by redimensioning the chamber and then was able to fire the same ammunition which had previously caused the problem--but now without incident.

It's one thing to be prudently skeptical. It's another to ignore reality.

Before you bother to ask, I have no intention of attempting to quantify "prudently skeptical". ;)
 
While your statements are technically correct, they are taking the idea of scientific skepticism beyond the pale of what is reasonable.

You've essentially decided upon threshold/burden of proof that insures no one will ever satisfy you as to what is causing the problem--UNLESS they choose one of the explanations that you prefer over the mismatch warning.
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I thank you for your opinion. I am NOT arguing for people to disregard the mismatch warning.

I also think that the first hand accounts of 223 pressure level loads popping primers in ARs demonstrates that the other factors cannot be denied, as well as 5.56 milspec loads popping primers in 5.56 chambers shows supports that as well. When there is no mismatch you cannot blame a mismatch, it MUST be something else. When there is a mismatch, if it doesn't happen every single time you pull the trigger, then odds are there is at least something else acting in concert with the chamber mismatch, a position you yourself have already stated.

In Iraiam's case, we know there was a chamber mismatch, we do NOT know if there was a long neck, secondary pressure spike, etc. So we don't know the full story about what happened.

As the experts YOU REFERENCED noted that "pressure rise was not dramatic" and the pressure traces we have available showed no pressure rise over 62k, I think that the thing to do is measure cases, looking for long necks, case head expansion, etc. So far the collected wisdom is "chamber mismatch, oh well" and chalked it up to "this happened, so this must be the cause."

That is not "beyond the pale" that is simply the same level of scrutiny I would expect from an engineer looking to get answers.

Until you can quantify something, you can't really understand it. I am seeking to understand something, and the conventional wisdom is an incomplete explanation because we see popped primers without mismatches.

Thank you for your time, and once again, I am not advising anyone to mismatch ammunition, I just want to understand why the standard explanation of a chamber mismatch doesn't explain why we see the same ammo failures when there isn't a mismatch.

Jimro
 
...the conventional wisdom is an incomplete explanation because we see popped primers without mismatches.
...

...I just want to understand why the standard explanation of a chamber mismatch doesn't explain why we see the same ammo failures when there isn't a mismatch.
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At an extremely superficial level, this might seem reasonable. But even a relatively simple analysis of what it actually means reveals either a serious problem with logical reasoning, or a basic lack of understanding of this topic in general.

The statement suggests that if any pressure-related failures occur in the absence of the mismatch, we should discount the mismatch warning/explanation as a cause for the failures that do occur during the mismatch.

It is equivalent to a child telling a parent that because other things besides a hot stove can burn a finger, the warning and explanation of how the stove can burn a finger is inadequate, incomplete and probably inaccurate.

In the same way that a hot stove is ONE thing that can burn a finger, an ammo/chamber mismatch is ONE thing that can cause pressures to rise above normal.

In the same way that a warning not to touch a hot stove can help a child to avoid burns is accurate, so it is true that a warning not to mismatch ammo/chambers can help a shooter avoid pressure related problems.

Just as touching the stove won't prevent ALL burns because hot stoves are not the exclusive cause of burns, so it is true that eliminating the mismatch won't eliminate ALL pressure related problems because the mismatch is not the exclusive cause of pressure related problems.

All of the failures discussed are the result of higher than normal pressure. The fact that there are other factors besides an ammo/chamber mismatch which can cause higher than normal pressure is NOT evidence that the mismatch can not cause higher than normal pressure.

It's not even sufficient to raise a reasonable doubt as to the validity of the mismatch warning, any more than the contention by the child that things other than hot stoves can burn would call into question the validity of the parent's warning about the hot stove.
 
Disagree all you want, but realize that you don't know if it was a long neck on the brass that raised pressure or if the powder went bad or if it was anything else.

All you really know is that you had a round lock up the rifle, and it hasn't happened again since you stopped using that lot of ammunition. Those two data points don't tell you that a chamber mismatch is to blame only that a mismatch is a possibility (along with the others mentioned in this thread).
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It was enough evidence for me, I will not be able to meet the level of evidence required to change anyone's mind, and I don't care, the OP asked for a 1st hand instance, this is what I have.

You can go ahead and shoot whatever you want in your rifles, but based on my first hand observations, I would be very careful about advising others to fire 5.56 NATO in a .223 chambered rifle, I won't be doing it, and would advise anyone to adhere to numerous manufacturer warnings.

I'm out.
 
JohnSKa,

Yes, explain it to me. What causes a secondary pressure spike?

Can you agree to the following two sentences?

It is easy to blame the mismatch as it is the "usual suspect" but if that same lot of ammo produces the same symptoms in a non-mismatched chamber, then it isn't the chamber, it is the ammo. And if you do have a mismatch, but don't bother to analyze the brass, you won't have any idea if it was an out of spec round.

Remember that we already agree that a mismatch will raise pressure and that I am not advocating for anyone mismatch their ammo.

Jimro
 
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