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Summary of Results from Oswald's Paraffin Tests


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Tom, I didn't put this directly in the summary of test results because it isn't a test result. But I did include it in its own section. Hopefully you will correct it for me.

What is the POST # that includes the caveats for the GSR tests?

Are you sure that the side of the cast that did not touch Oswald's cheek actually tested positive on the NAA test? (I knew that it had more barium than on the side that touched Oswald's face. But I didn't know that it tested positive.)

That was a bad choice of terminology on my part. I meant that the WRONG SIDE of the cheek CAST tested "positive" for Barium(?) in the sense that Barium was present were it should NOT have been. I did NOT mean that there was enough GSR on the "outside" of the cheek cast for the Test Result to be Positive, because I do NOT know HOW MUCH GSR was present on the "outside" of the cast.
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The question that I have regarding a positive result in the Nitrate test :

HOW MANY specks of Nitrate are required for a POSITIVE result? ONE? Conclusions drawn from these test results appear to be subjective at best...

Tom

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Tom, I didn't put this directly in the summary of test results because it isn't a test result. But I did include it in its own section. Hopefully you will correct it for me.

What is the POST # that includes the caveats for the GSR tests?

Are you sure that the side of the cast that did not touch Oswald's cheek actually tested positive on the NAA test? (I knew that it had more barium than on the side that touched Oswald's face. But I didn't know that it tested positive.)

That was a bad choice of terminology on my part. I meant that the WRONG SIDE of the cheek CAST tested "positive" for Barium(?) in the sense that Barium was present were it should NOT have been. I did NOT mean that there was enough GSR on the "outside" of the cheek cast for the Test Result to be Positive, because I do NOT know HOW MUCH GSR was present on the "outside" of the cast.

Go to post #1 and look for the section titled "Evidence Tampering." You'll see that I cobbled something together there that sounds good (to me) but probably isn't all correct.

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The question that I have regarding a positive result in the Nitrate test :

HOW MANY specks of Nitrate are required for a POSITIVE result? ONE? Conclusions drawn from these test results appear to be subjective at best...

Tom

And why do they come in specks?

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Sorry, Pat, I cannot accept this photo as valid. I have shot too many bolt action rifles, and been near bolt action rifles being shot, to believe this. I would think, after all these years, I would have noticed this before; especially hunting in cold damp weather.

Here is a diagram of the inside of a bolt action rifle barrel, showing a cartridge in the chamber.

01-GunnersDen-specification-rifle-barrel

Note that chamber and barrel are machined from one piece of steel. Not shown is the face of the bolt that holds the cartridge in place.

When the cartridge is fired, the bullet does not immediately leave the cartridge. It requires great internal cartridge pressure, from the combustion of its gunpowder, to overcome inertia and begin moving the bullet down the barrel. Before the bullet leaves the cartridge, with the cartridge being a sealed unit, these pressures act on the thin walls of the brass cartridge, moulding it to the inside of the chamber and preventing gases from escaping past the cartridge toward the shooter.

Unless that photo was re-touched, we are likely looking at the result of a ruptured brass cartridge or ruptured primer. When such a thing occurs, there are small gas vent holes on the sides of the forward end of the receiver (many times only one) that direct gases harmlessly out to the side, instead of toward the shooter's face. The beginning of the plume, in the photo above, is precisely where Winchester puts the single gas vent on their Model 70.

23056950_2.jpg?v=8D2AE48DC97B770

Gas vent shown as small hole on the forward part (right) of the Model 70 receiver, just under scope base and serial number.

Seriously, Pat, there is as much of a plume coming from the bolt action rifle as there is from the M-1. How could that be possible?

Edited by Robert Prudhomme
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Sorry, Pat, I cannot accept this photo as valid. I have shot too many bolt action rifles, and been near bolt action rifles being shot, to believe this. I would think, after all these years, I would have noticed this before; especially hunting in cold damp weather.

Here is a diagram of the inside of a bolt action rifle barrel, showing a cartridge in the chamber.

01-GunnersDen-specification-rifle-barrel

Note that chamber and barrel are machined from one piece of steel. Not shown is the face of the bolt that holds the cartridge in place.

When the cartridge is fired, the bullet does not immediately leave the cartridge. It requires great internal cartridge pressure, from the combustion of its gunpowder, to overcome inertia and begin moving the bullet down the barrel. Before the bullet leaves the cartridge, with the cartridge being a sealed unit, these pressures act on the thin walls of the brass cartridge, moulding it to the inside of the chamber and preventing gases from escaping past the cartridge toward the shooter.

Unless that photo was re-touched, we are likely looking at the result of a ruptured brass cartridge or ruptured primer. When such a thing occurs, there are small gas vent holes on the sides of the forward end of the receiver (many times only one) that direct gases harmlessly out to the side, instead of toward the shooter's face. The beginning of the plume, in the photo above, is precisely where Winchester puts the single gas vent on their Model 70.

23056950_2.jpg?v=8D2AE48DC97B770

Gas vent shown as small hole on the forward part (right) of the Model 70 receiver, just under scope base and serial number.

Seriously, Pat, there is as much of a plume coming from the bolt action rifle as there is from the M-1. How could that be possible?

Robert,

While what you say rings true to me, it is hard for me to dismiss the words of experts.

The pictures Pat posted came from the 2000 book Current Methods in Forensic Gunshot Residue Analysis by A. J. Schwoeble and D. L. Exline. I can't think of any reason why the authors would misrepresent their pictures of plumes.

Also, I have found another modern book that states that GSRs are emitted by bolt-action rifles. The book, published in 2006, is Terminal Ballistics - A Text and Atlas of Gunshot Wounds by M. J. Dodd. Here's a quote from it:

"Gas and fine particulate matter will escape from spaces between the back of the cylinder and the frame in the case of a revolver and from the breech and opened slide in the case of a semiautomatic pistol. Bolt action rifles and shotguns tend to expel less material onto the firing hand, as the closed chamber and breech are of a tighter fit. GSR may, however still be detected."

Perhaps the bullet casing doesn't expand perfectly tight in every bolt-action rifle.

BTW, when you said this:

Seriously, Pat, there is as much of a plume coming from the bolt action rifle as there is from the M-1. How could that be possible?

I don't think you looked carefully enough at the plume coming from the M-1. The plume form the M-1 is much greater than that from the bolt-action rifle. It's just that it has dispersed to the point that it is harder to see near the gun. But it is easy to make out over the shooters head.

If you do a quick scroll through the pictures in the book, you will see that the bolt-action rifle's plume is indeed very small. Especially when compared to that of the revolvers shown.

Edited by Sandy Larsen
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The plume from the M-1 is greater because it is longer. Being a semi-automatic rifle, this suggests the rifle in the photo has, within a couple of seconds of this photo being taken, fired several shots. Therefore, more gas has escaped from its piston operating system, as it was designed to do. This is why the plume appears to have "dispersed" (disburse means to pay out, as in from a fund) over the shooter's head.

"I don't think you looked carefully enough at the plume coming from the M-1. The plume form the M-1 is much greater than that from the bolt-action rifle. It's just that it has disbursed to the point that it is harder to see near the gun. But it is easy to make out over the shooters head."

Even if a worn bolt action chamber is oval shaped, the expanding brass of the cartridge will swell outwards and "fire fit" to this irregular shape, and make an effective seal against escaping gases. This is a phenomenon that plagues handloaders that practice a type of cartridge re-sizing called "neck sizing", in which only the neck of the cartridge is re-sized.

I can consider trace elements escaping from this seal, but not the great plume depicted in this photo.

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This is why the plume appears to have "dispersed" (disburse means to pay out, as in from a fund) over the shooter's head.

Dam spelling checker can't reed my mind.

(P.S. Yes, I know the difference between disburse and disperse. Though apparently my fingers don't. ;) )

Edited by Sandy Larsen
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The paraffin tests are discussed beginning on page 560 of the Warren Report, which can be found here.

Regarding the nitrate tests, the WC did report the positive results on the hands and the negative result on the right cheek. But then it notes that "....the test is completely unreliable in determining either whether a person has recently fired a weapon or whether he has not."

Regarding the NAA tests for barium and antimony, the WC reported that the greater amount of barium found on the outside of the cheek cast "rendered it impossible to attach significance to the presence of these elements on the inside surface."

As for the NAA hand tests, the following two points are made:

  • "Barium and antimony were found to be present on both surfaces of all the casts and also in residues from the rifle cartridge cases and the revolver cartridge cases. Since barium and antimony were present in both the rifle and the revolver cartridge cases, their presence on the casts were not evidence that Oswald had fired the rifle."
  • "Furthermore, while there was more barium and antimony present on the casts than would normally be found on the hands of a person who had not fired a weapon or handled a fired weapon, it is also true that barium and antimony may be present in many common items....However, the barium and antimony present in these items are usually not present in a form which would lead to their adhering to the skin of a person who had handled such items."

So, in summary, the WC reported that:

  1. The nitrate tests are unreliable, and so they indicate nothing.
  2. The NAA test on the cheek was inconclusive, and so it indicates nothing.
  3. The NAA tests on the hands may not have come from common items known to contain barium and antimony. (Or they may have.) Regardless, they may have come from merely handling the revolver and rifle.

Does anybody believe I have misrepresented the WCR with any of these three summary items? I ask because I plan on incorporating them into The Summary. (Actually, only item #3 is new.)

Edited by Sandy Larsen
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The paraffin tests are discussed beginning on page 560 of the Warren Report, which can be found here.

Regarding the nitrate tests, the WC did report the positive results on the hands and the negative result on the right cheek. But then it notes that "....the test is completely unreliable in determining either whether a person has recently fired a weapon or whether he has not."

Regarding the NAA tests for barium and antimony, the WC reported that the greater amount of barium found on the outside of the cheek cast "rendered it impossible to attach significance to the presence of these elements on the inside surface."

As for the NAA hand tests, the following two points are made:

  • "Barium and antimony were found to be present on both surfaces of all the casts and also in residues from the rifle cartridge cases and the revolver cartridge cases. Since barium and antimony were present in both the rifle and the revolver cartridge cases, their presence on the casts were not evidence that Oswald had fired the rifle."

  • "Furthermore, while there was more barium and antimony present on the casts than would normally be found on the hands of a person who had not fired a weapon or handled a fired weapon, it is also true that barium and antimony may be present in many common items....However, the barium and antimony present in these items are usually not present in a form which would lead to their adhering to the skin of a person who had handled such items."

So, in summary, the WC reported that:

  1. The nitrate tests are unreliable, and so they indicate nothing.

  2. The NAA test on the cheek was inconclusive, and so it indicates nothing.

  3. The NAA tests on the hands may not have come from common items known to contain barium and antimony. Or they may have. Regardless, they may have come from merely handling the revolver and rifle.

Does anybody believe I have misrepresented the WCR with any of these three summary items? I ask because I plan on incorporating them into The Summary. (Actually, only item #3 is new.)

One of my motivations for writing a summary of paraffin test results was to see what claims CTers can honestly make about the tests. Because, as I mentioned earlier, I like to tell LNers that "there is no evidence that Oswald fired a rifle that day."

I wanted to draw reasonable conclusions based on the evidence provided in the 26 volumes of evidence. Conclusions that would clash with those of the Warren Commission.

To my great surprise, as indicated in my prior post which I quote here, the conclusions made by the WC already AGREE with my statement that there is no evidence Oswald shot a rifle that day. Not only that, but neither is there evidence that Oswald shot a revolver.

I had merely assumed that the WC claimed the paraffin tests indicated guilt on Oswald's part.

There remains a caveat, though. And that is, the paraffin tests may be discussed in another section beside the one I read. What I read begins on page 560 of the WCR. If anybody knows of another section commenting on the paraffin tests, please let me know. (Where is DVP when you need him?)

I have made changes to The Summary in post #1 to reflect what I read in the WCR. See the edits in red if you are interested in tracking the changes.

BTW, The Summary is getting to be a little unwieldy. I will try to clean it up later. Right now I am still trying to gather information.

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It seems to me that there is a fundamental problem with both the nitrate test and the NAA test for barium and antimony. First, they both are prone to producing false positives because those chemicals are all found in common substances. Second, they are both prone to false negatives because the accused could have washed his or her hands before being tested.

I have edited The Summary in post #1 to reflect this. These edits are found under the following section heading:

[Preliminary] Honest Independent Conclusions

Still, the tests could be useful in cases where it is known that the accused didn't wash his hands.

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Here is the plume study for the Winchester 70, which is presented as an example for a bolt-action rifle.

Plumewinchester70boltaction.png

01-GunnersDen-specification-rifle-barrel

I have a theory that may explain why there can be a plume of smoke coming from the cartridge end of a gun barrel.

The gun is fired. The gun powder burns and the heat causes the cartridge to expand to the point where it blocks the passage of gas between it and the bore. The high pressure of the hot gas propels the bullet down the barrel.

The temperature of the gas diminishes dramatically as it expands. (This is a fundamental principle of gasses which is exploited for refrigeration.) Furthermore, the remaining heat in the propellant is dispersed along the length of the barrel. So the propellant is probably no longer heating up the cartridge.

In the meantime, the cartridge has lost most of its mass and is just an empty shell. Nearly the whole thing is in contact with the relatively cold, massive barrel. The heat is quickly transferred from the lightweight shell to the heavy barrel. The shell therefore contracts to the point where it is not making tight contact with the barrel.

This is when the gas passes between the cartridge and the bore and is expelled. This occurs just before the bullet exits the barrel.

I don't know if this is what happens. But it makes sense to me.

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Hi Sandy

This is not a bad theory, although you are missing one thing.

The bullet takes about .002 seconds to transit the length of the barrel before it exits. After the bullet exits, the propellant gases are no longer sealed in the barrel by the bullet. Even if the cartridge case did shrink, there is nothing in the barrel under pressure to escape past it.

It is interesting to note that, with a bullet passing through a barrel in .002 seconds, it is possible to wear out a barrel in just six seconds, or the equivalent of 3000 rounds passing through te barrel.

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