Robert Prudhomme

Hi Steve

I don't believe I've seen you on this forum before. Welcome.

I believe shots came from at least two different sources; behind and in front of the limo. I also believe the plotters of the assassination did not intend to have this seen as the work of a lone nut, and fully intended to blame the assassination on a group such as the Cubans. The very fact they chose to assassinate JFK in broad daylight in front of a large crowd speaks volumes about this.

I think the most important thing on their minds was allowing the shooter(s) behind the limo the opportunity to make their egress, whether it was from the TSBD, the Dal-Tex Building or the County Records Building. The shooter in front of the limo, whether he was on the north or south knoll, or the underpass, was already on the ground, and didn't need nearly as much time to escape. Besides, there is a very good chance the shooter in front of the limo was merely a backup and was only supposed to shoot if the other shooter(s) were unable to eliminate JFK.

How this was accomplished is a bit complicated, and I will explain my theory in response to the post David Josephs made.

Here is one for you, Dave. Did you know there is a way to make a shot originating from behind the limo appear, to ear witnesses, to have originated from down near the Grassy Knoll?

Do I have to hit people over the head around here to wake everyone up?

The guns are now considered to be collectable curiosities that are unsafe to shoot.

Considering the popularity of this alteration at the time I guess safety wasn't much of a factor.

Did you see my comments in post #143?

Considering the expansion of the cases I suspect they were not so easy to remove after firing. Yet LHO lingered at the murder scene long enough to remove them AND reload. Apparently this wasn't a dumb enough idea, so he also left his brass at the crime scene. IIRC, a civilian placed the spent brass in a cigarette package and turned it over to the police. Do we know the name of this helpful fellow? Or like the fellow who gave the description of the DP shooter, not one of these highly trained and experienced cops thought to ask him his name.

Didn't LHO also leave his wallet at the crime scene? But he didn't stop to pick it up, because he STILL had one wallet on him when he was picked up, and had several more at various other locations...

I'm actually glad this topic came up. I had seen vague references being made to there being something odd about Oswald's alleged revolver but I never looked that closely at the subject before. As usual, truth is stranger than fiction, and a lot more interesting to boot.

By now it should be obvious to everyone here that there is something drastically wrong with the Altgens 6 photo, seen below:

This photo corresponds in time to the moment frame z255 of the Zapruder film was exposed. According to the WCR, two shots from a 6.5mm Carcano M91/38 short rifle have just been fired from a position slightly behind these spectators seen here and 62 feet above them; 3.5 seconds and 5.2 seconds before this photo was taken.

At the very MINIMUM, the loudness of these shots would have been 130 decibels. However, if the sound level one meter from the muzzle of the Carcano was 157 decibels, as reported to the HSCA, there is a strong possibility these spectators heard gunshots in excess of 130 decibels.

If the threshold of pain is at 120 decibels, why is there no reaction whatsoever seen on the faces of the spectators?

"4 .3 Loudness and Apparent Size of Acoustic Image

All observers rated the rifle shots as very very loud, and they were unable to understand how they could have been described as a firecracker or backfire . Only the pistol, which was subsonic, produced a moderate loudness ."

"Analysis of Earwitness Reports Relating to the Assassination of President John F. Kennedy by D.M. Green 1979"

http://www.history-matters.com/archive/jfk/hsca/reportvols/vol8/pdf/HSCA_Vol8_AS_3_Earwitness.pdf

This report was presented to the HSCA.

The authors of this reported also stated that, at one meter from the test rifle (C2766), the muzzle blast was measured at 157 decibels and that, at 30 feet from the muzzle, the sound was measured at 137 decibels. Nowhere does this report state whether these measured distances were going back or forward from the muzzle, or whether the measurements were taken 90° out from the side of the rifle.

Hey Tom

Just out of curiosity, I visited a couple of forums that dealt mainly with S&W revolvers. Nobody had anything good to say about the .38 S&W/.38 Special conversions, and most of the experts there advised against shooting these revolvers at all. I guess there is also concern that the original .38 S&W revolver was never designed to withstand the higher pressures from the much larger .38 Special cartridge.

The more I think about it, this conversion seems like a bad idea, bordering on the insane, actually.

Take a long skinny .38 Special cartridge and insert it into a chamber where only the front 1/3 of the casing is in contact with the chamber. Fire the cartridge and the bullet rattles down a throat .004 inch too large for it that may or may not properly align the bullet with the barrel. Finally, the bullet gets to rattle down a barrel that is also .004 inch too large for it.

Is this the kind of revolver that used to blow up in a shooter's hand?

Hi Tom

I just read your Edit. I think we are on the same track here, just expressing it to each other a little differently.

As the size of this gap would determine the volume of GSR escaping through it, the real questions should be how much time was allowed between shots (giving the metal a chance to cool down and contract) and was an equal amount of time allowed between each shot?

Bob, this makes perfect sense to me. What would be needed would be measurements of this gap, and cylinder temperature after firing multiple shots. The expanding cylinder would increase to a higher temperature following each shot, and the gap would decrease. This could decrease the amount of GSR expelled, or simply increase its exit velocity due to an increased pressure at the gap. This could affect either the amount of GSR, its dispersal pattern, or both.

According to the WC, JDT was shot 3 times presumably as rapidly as possible, and after a brief pause, two additional shots were fired into his head. I'm guessing that the interval between shots 3 and 4 would not have allowed appreciable cooling.

However, does this explain the erratic plus and minus variances in Mr. Speer's tables? As you say, if the time between shots was long enough for cooling and the intervals differed, then yes. But if the shots were fired at brief equal intervals as they should have been, then some other factors would be required.

Were these revolvers 'used' and in typical used gun condition? How accurate was the indexing mechanism that locked the cylinder bores into alignment with the barrel? Was the cylinder face in proper condition? The rechambered .38s were popular around the date of Guinn's testing. One or more of these MAY been used. Comments on multiple gun sites state that the cylinder bores of these re-chambered 38s were frequently off-round and had high and low spots in the bore. Any of these factors, and especially combinations of them would, at least in my non-gunsmith opinion, produce erratic results in GSR quantity and dispersal.

If re-chambered .38s were NOT included in Guinn's tests, then considering the number of off-standard features of "LHO's" gun, how closely would those results resemble Mr. Spears' proffered test results?

Yes, I believe all of these variables, including the converted .38 Special, could produce some very puzzling and inconsistent test results if not allowed for. I seriously doubt Guinn or the DPD would have fully understood the problem here.

If you look again at the diagrams, you will see that the .38 Special is smaller in diameter in both bullet and brass casing.

Bullet = .357 inch

Casing = .379 inch

The .38 S&W is larger in diameter in both bullet and brass casing.

Bullet = .361 inch

Casing = .3855 inch

Yes, the Special AMMO is longer, but narrower than the non-Special AMMO. And yes, I do know that the casings in both are larger in diameter than the bullet. This is what I have maintained all along. If you believe I have thought otherwise, than we are misunderstanding each other.

"...the throat diameter for the .38 S&W would be .361 inches...and would be drilled out to .379 inches to accommodate the .38 Special casing."

You are stating here that the NON re-chambered cylinder throat of a .38 S&W is .361", and the rechambered throat would be .379". If the rechambered throat MUST be drilled to the same .379 diameter of the Special's casing, then the original throat diameter MUST be equal to the .3855 diameter of the non-special casing. Yet, you are stating here that is is NOT .3855, but .361".

Also, as I've stated in previous posts, the data I have gotten from multiple sources is that the above-mentioned throat diameter for the NON re-chambered .38 SW is .358, not .361.

If you don't believe the .358 diameter is correct then we're at an impasse until we can find a manufacturer's spec.

Tom

Hi Tom

Well, I can't see how a non-rechambered .38 S&W could have a throat of .358 inches in diameter, and a bullet diameter of .361 inches in diameter. The throat in the chamber has no riflings, these do not start until the bullet has crossed the gap and is in the barrel. How could a .361 inch bullet pass through a .358 inch throat?

The brass casing of the .38 S&W is .3855 inches in diameter at the neck, but it is a very short cartridge, at just .775 inches in length. The .38 Special cartridge is much longer, at 1.155 inches. It is this extra .380 inches in case length (1.155 - .775 = .380) that allowed the conversion of the .38 S&W to a .38 Special. The chamber was bored from .361 to .379 only for .380 inch, from the point where the neck of the .38 S&W casing neck stopped in the chamber, to the point were the longer .38 Special's case neck would stop. The remaining part of the chamber (now in the throat) was left at .361 inch diameter for the .357 inch .38 Special to travel through. In other words, only the front 32% of the .38 Special casing, plus the rim, would be in contact with the chamber, explaining the characteristic "swollen cartridge base" seen with empty casings from one of these converted revolvers.

This is another reason the .38 S&W/.38 Special conversion was not such a good idea. The throat had to be fairly precise, as it guided the bullet on its way to the cylinder gap where it crossed over and entered the barrel. If the throat was .361 inch diameter, and the bullet was only .357 inch diameter, it would be quite a sloppy ride down the throat, and the bullet may or may not be properly lined up with the barrel when it crossed the gap. I could see rapid wear and erosion of the barrel, and possibly even a threat to the shooter, should the misalignment of bullet to barrel become too great.If nothing else it, along with the oversized barrel for the .357 inch diameter bullet, would certainly affect accuracy. However, as this was, with its short barrel, most definitely an "up close and personal" weapon, it is unlikely whether or not anyone ever noticed a lack of accuracy.

Tom Neal said:

"No, it is NOT beside the point. A revolver has 6 different chambers. Each shot would produce DIFFERENT characteristics. This would produce different GSR levels. The only question is how MUCH different. If the pattern repeated after a reload we would have an answer. As I've ALREADY pointed out, someone with a greater knowledge of guns may spot something you didn't know. e.g. Contrary to your reply, it DOES matter if they were all revolvers or not."

I think the answer to this question, assuming all the weapons in the testing were revolvers, lies in this photo:

As can be seen in this photo, there is quite a large gap between the chamber of the revolver, holding the cartridges, and the barrel of the revolver. This is known, in some circles, as the "barrel cylinder gap" and, while it may appear to be poor workmanship, this large gap is a necessary component of a revolver, without which it could not function.

The above photo demonstrates just how ridiculously large this gap is, and the great potential there is for losing propellant gases here.

The reason this gap is so large is that, with each shot fired, the metal components on either side of this gap heat up and expand. If the gap, in a cold revolver, was made small enough to almost seal this gap off, by the time the second shot was fired the metal on either side of this gap would have expanded to the point the two surfaces would be in contact with each other, and the chamber would no longer turn.

If the metal components did not expand with each shot, there would be virtually no barrel cylinder gap.

As the size of this gap would determine the volume of GSR escaping through it, the real questions should be how much time was allowed between shots (giving the metal a chance to cool down and contract) and was an equal amount of time allowed between each shot?

Hi Tom

Close but,

the throat diameter for the .38 S&W would be .361 inches, the same diameter as the .38 S&W bullet, and would be drilled out to .379 inches to accommodate the .38 Special casing.

The .38 Special bullet diameter is .357 inches.

IF the throat diameter of the cylinder bore of a .38 SW actually is .379 per your statement above, then the .38 Special cartridge with its .357 diameter would fit ALL the way into the chamber despite its greater length. However, it does not. It only goes in about 2/3 of its length. The throat has to be increased in diameter with a reamer by the difference in length of the S v. the SW.

I'll see if I can find a diagram, but subject to my memory the cylinder throat diameter is smaller than the bore diameter in both the SW and Special revolvers.

Tom

Hi Tom

If you look again at the diagrams, you will see that the .38 Special is smaller in diameter in both bullet and brass casing.

Bullet = .357 inch

Casing = .379 inch

The .38 S&W is larger in diameter in both bullet and brass casing.

Bullet = .361 inch

Casing = .3855 inch

The manufacturer would not make the chamber of the .38 S&W .379 inches in diameter, if the diameter of the casing was .3855 inches and flared out to .3865 inches at the base of the cartridge.

I did not say the .38 S&W chamber was .379 inches in diameter, and I don't know how you got that impression.

Obviously, the .38 S&W chamber narrows down from .3855 inches to .361 inches at the point where the bullet meets the neck of the brass casing. It is this .361 inch diameter section of the chamber that must be bored out to accommodate the longer .38 Special casing with a diameter of .379 inches.

I think I just got it. If the .38 S&W brass casing was only .775 inches long, and the .38 S&W chamber was long enough to accommodate the longer .38 Special brass casing (1.155 inches long), did that mean the forward part of the .38 S&W chamber narrowed down to the diameter of the .38 S&W bullet, that diameter being .361 inch? Therefore, all they had to do was drill the narrower (.361 inch) part of the chamber out to .380 inch to accommodate the .379 inch diameter .38 Special brass casing. Perfect.

And THAT is why everyone speaks of the .38 Special casing being swollen out at the base, as it is trying to fill a chamber .3855 inches in diameter.

P.S.

I'm still wrong. The .38 S&W chamber is .3855 inches at the forward end, but flares out to .3865 inches toward the base.

Bob,

In my earlier post I incorrectly stated the bullet diameter as the cylinder bore diameter, but I see you have used the correct dimensions.

Still from memory, but I believe the cylinder throat diameter is only .358" so what they are doing is reaming out the throat to accommodate the .379" diameter .38 Special cartridge. The throat is long enough to allow full insertion of the longer bullet and still retain an adequate throat length. So the first 1/3 of the cartridge is inserted into the part of the cylinder bore that matches the diameter of a .38 Special revolver cylinder bore.

I should have time tomorrow to check the throat diameter from my records which I made at least 3 years ago. Hopefully, I can find them...

Hi Tom

Close but, the throat diameter for the .38 S&W would be .361 inches, the same diameter as the .38 S&W bullet, and would be drilled out to .379 inches to accommodate the .38 Special casing. The .38 Special bullet diameter is .357 inches, while the .38 S&W bullet diameter is .361 inches; .004 inch difference

This is why re-chambering a .38 S&W to a .38 Special is a somewhat questionable exercise, as you are now shooting a .38 Special bullet that is .004 inch smaller in diameter through the .38 S&W barrel. There will be far less of the riflings gripping the bullet and there is also a chance for propellant gases to blow past the bullet in the barrel. However, considering that the barrel of Oswald's alleged revolver was cut shorter anyways, and that most revolvers are used within spitting distance of their victims, making accuracy unimportant, these things probably don't make a lot of difference.

P.S.

Are there any photos available of spent bullets fired from Oswald's alleged revolver?

I think I just got it. If the .38 S&W brass casing was only .775 inches long, and the .38 S&W chamber was long enough to accommodate the longer .38 Special brass casing (1.155 inches long), did that mean the forward part of the .38 S&W chamber narrowed down to the diameter of the .38 S&W bullet, that diameter being .361 inch? Therefore, all they had to do was drill the narrower (.361 inch) part of the chamber out to .380 inch to accommodate the .379 inch diameter .38 Special brass casing. Perfect.

And THAT is why everyone speaks of the .38 Special casing being swollen out at the base, as it is trying to fill a chamber .3855 inches in diameter.

P.S.

I'm still wrong. The .38 S&W chamber is .3855 inches at the forward end, but flares out to .3865 inches toward the base.

"This is still from memory, so subject to verification - The smaller diameter, but longer .38 Special cartridge will only fit 2/3 of its length into the cylinder, so the chamber is bored at the smaller (.357) diameter until long enough to accept the entire cartridge. The first third of the cartridge fits into the correct diameter bore, but the remaining 2/3 thirds is a loose fit due to the larger .38 S&W bore diameter. A .38 Special cartridge fired in a re-chambered weapon produces a spent hull that has an expanded diameter at its end due to 2/3 of the cartridge residing in the oversize bore when it was fired."

Hi Tom

This is the part I don't understand, assuming they kept the original .38 Victory revolving chamber and modified it to accommodate the .38 Special cartridge.

If the entire .38 S&W chamber was .3855 inches in diameter, and the .38 Special cartridge was a mere .379 inches in diameter, how could you bore the .38 S&W chamber out, if you needed to make it smaller?

Thought I'd share this lovely photo with you, showing the air gap flash from a .38 Special revolver.

To understand why .38 calibre handguns shoot a bullet much smaller in diameter than .380 inches, we have to look at the evolution of revolvers and brass cartridges.

The original .38 calibre cartridge, the .38 Short Colt, came about when .36 calibre cap and ball Navy revolvers were being converted to shoot the newly developed self-contained brass cartridges. It just happened that the chambers in the revolving part of the .36 calibre revolvers were .374 inch in diameter, which was rounded off to .38 very quickly. This will likely leave most of you scratching your heads, as everyone knows a bullet is smaller in diameter than its cartridge. However, let me introduce you to an archaic bullet design known as a "heeled" bullet. They have all but disappeared, and are seen today only in .22 calibre rimfire ammunition.

As seen above, a heeled bullet (right) has a stepped shoulder that allows it to be loaded into a brass cartridge of the same diameter as the widest part of the heeled bullet.

This worked well for many years but, with the introduction of smokeless powder, the heeled bullet design fell out of favor. The chamber size of the revolver was kept but the barrel reduced to shoot a new round, the .38 Smith & Wesson. This had a bullet diameter of .361 inch and an actual bore diameter (calibre) of, I believe, .352 inch, although I have been unable to confirm this. The .38 Special was nothing more than a souped up version of the .38 S & W that shot a slightly smaller bullet of .357 inches diameter.

From what we are told, this is what Oswald's alleged revolver was re-chambered for (.38 Special), and this was the ammo he was using. However, the story goes much deeper than this.

Following the First World War, the British Army wanted to move away from their ,455 calibre revolvers to something that shot a smaller cartridge, and finally settled on a cartridge referred to as the .38/200 Revolver Mk. I round; basically a modified .38 S & W round loaded with a 200 grain lead bullet. During the Lend-Lease Program of World War II, the Smith & Wesson Model 10 was manufactured in the USA for supply to British and British Commonwealth troops, to the tune of 570,000 revolvers. Their serial numbers ha a "V" prefix, and they were known as the Smith & Wesson Victory Model.

Following the war, many of these revolvers found their way back to North America as military surplus and, being cheap, entrepreneurs bought them up quickly and attempted to market them en masse. The only problem was that the .38 Special fired a bullet with a much greater velocity than the .38 S & W, and everyone wanted a .38 Special.

So, the S & W Victory Models were converted to shoot .38 Special cartridges by re-chambering. How they did this precisely is a bit of a mystery to me unless, of course, the .38 S & W revolving chamber was merely swapped out for a .38 Special revolving chamber. You see, they simply couldn't just drill the chambers out to a larger size, as the .38 S & W chamber was already .3855 inches in diameter, and the .38 Special chamber was a mere .379 inches in diameter. A chamber liner, possibly?

It gets better, though. The .38 Special barrel has a bore diameter of .350 inches, and a groove diameter of .357 inches, meaning it shoots a bullet .357 inches in diameter. HOWEVER, the .38 S & W and the British .38/200 both fired a bullet .361 inches in diameter, a full .004 inch larger than the .38 Special bullets.

Coincidentally, and quite an amazing coincidence at that, this is the same problem that plagued the vast numbers of Italian 6.5mm Carcano rifles that found their way onto the sporting market, following WW II. The vast majority of 6.5mm rifles had a groove diameter of .264 inches, and required a bullet that was also .264 inches in diameter. The 6.5mm Carcano, while retaining the same 6.5 mm calibre as other 6.5's, had extra deep rifling grooves, and required a bullet .268 inches in diameter for accuracy. Despite the vast amounts of misinformation posted on shooting forums by disinfo agents, shooting the smaller diameter bullets in the Carcano was one of the leading contributing factors to the development of the myth that Carcanos were inaccurate rifles.

Considering the shallow rifling grooves in a .38 S & W barrel, I would be surprised if the .38 Special bullets fired from Oswald's alleged revolver had rifling impressions on them that amounted to more than light scratches.

More nails in the height issue coffin.

Note the length of Oswald's shirt. He was standing one step down.

Credit: Tony Fratini

Willis 8, reflective strip, credit: BK

From Robin Unger's gallery

Holy crap, Bart, what a very obvious yet ground shaking discovery! I would have sworn PM was on the top landing, way back in the corner, but this changes everything. It would be interesting to see what our friends "Dumb & Dumber" over at the other forum would say when confronted with this.

P.S.

Bottom photo, guy in the suit, centre of photo; doesn't he look like a dead ringer for the late and missing Teamster president Jimmy Hoffa?

Oh boy, what a can of worms you have opened here, Tom!

Although I'm not big on handguns, I thought I understood the whole .38 Smith & Wesson vs, .38 Special thing, until I began delving into the history of these handguns.

The first thing I have to ask about Oswald's alleged revolver is, was it merely re-chambered for .38 Special ammo, or was it also re-barrelled for .38 Special?

Perceptions of Increases in Decibel Level

Imperceptible Change

1dB

Barely Perceptible Change

3dB

Clearly Noticeable Change

5dB

About Twice as Loud

10dB

About Four Times as Loud

20dB

Decibel (Loudness) Comparison Chart

Here are some interesting numbers, collected from a variety of sources, that help one to understand the volume levels of various sources and how they can affect our hearing.

Environmental Noise

"When comparing the amount of residue for six firings with the amount of residue for one firing, moreover, it was clear that the total for six was less than the average for one multiplied by six."

Well, Pat, don't leave us hanging like this. How MUCH greater was the total GSR for six shots than for one shot? Or, to put it in another perspective, how MUCH less was the total GSR for six shots than the average for one shot multiplied by six?

"The amount of deposit is not linear with the number of firings...One possible explanation is that additional blasts blow or shake off some of the deposits."

I just want to comment that, in my searches for this thread, I did come across a statement in a modern (post-1995) book that says that the deposits do accumulate. I would have made a note of it had I known that there might be some disagreement on the subject.

They accumulate but not in a linear fashion. I saw that someone was under the impression there was a linear relationship between the number of shots fired and the amount of residue. And the articles and textbooks I've read dealing with this subject insist this just isn't true.

If they do accumulate, shot by shot, but not in a linear fashion, in what fashion do they accumulate, Pat? The word "accumulate" tends to imply that, with each shot, there would be more GSR on a person's hands.