Summary of Results from Oswald's Paraffin Tests

[Tom Neal]

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.

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

This is what I've been saying all along, and you've been saying that the narrower Special Ammo should fit without any boring. See your post #122 and the quote below from your post #125:

"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?"

EDIT the following test added: The issue with inserting the .38 Special ammunition into a .38 S&W is that the .379 diameter CASE of the Special is larger than the .361 diameter of the S&W BULLET, and the special case is LONGER than the S&W case. Thus, the Special ammo stops when the Special CASE encounters the area that the smaller diameter S&W BULLET is small enough to fit inside of. This is WHY as I stated earlier .38 Special ammo can NOT be fully inserted into a .38 S&W revolver that has NOT been rechambered.

Tom

Edited May 22, 2016 by Tom Neal

[Tom Neal]

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?

Edited May 22, 2016 by Tom Neal

[Tom Neal]

ERROR - POST DELETED

Edited May 22, 2016 by Tom Neal

[Robert Prudhomme]

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.

Edited May 22, 2016 by Robert Prudhomme

[Robert Prudhomme]

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.

Edited May 22, 2016 by Robert Prudhomme

[Robert Prudhomme]

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.

[Robert Prudhomme]

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?

Edited May 22, 2016 by Robert Prudhomme

[Tom Neal]

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?

There are many warnings posted that this common alteration of the .38 SW is too dangerous to use. It may be the genesis of statements that "LHO's" gun wouldn't fire. Stories about bent firing pins etc, MAY be based on DPD's N.M. MacDonald's *story* that LHO tried to shoot him but the gun mis-fired. It would be nice to see an actual FBI Lab doc rather than testimony from people that are proven liars.

[Sandy Larsen]

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?

These are all very good points. (Including, of course, Robert's observation regarding the expanding heated chamber.)

From studying all this, and the table Pat posted, I still don't see any reason to believe that GSR from multiple shots don't accumulate in a linear fashion. (Even though that appeared to be the case in the small study whose results were recorded in Table 4) So far it seems to me that:

1. GSR does accumulate, presumably in a linear fashion.

2. But the amount of GSR deposited from each shot can vary dramatically.

3. Observing the result of list items #1 and #2 may lead one to conclude that the accumulation isn't "linear." But this, to my way of thinking, wouldn't be correct... technically speaking.

   Rather, the proper conclusion (IMO) would be that GSR accumulates -- presumably in a linear fashion -- but the amount deposited from each shot can vary widely. (A larger study would be required to determine if the accumulation isn't linear. Or at least a convincing explanation as to why it shouldn't be.)

4. Even though, say, five shots may not produce close to five times as much deposited GSR, it will increase the likelihood of GSR deposits being present and in greater amounts, than had only one shot taken place. And thus, it will decrease the odds of a false-negative test result occurring.

Edited May 23, 2016 by Sandy Larsen

[Tom Neal]

PAT SPEER, on 17 MAY 2016 at 03:48 A.M. said:

I've decided to go ahead and put some of the documents I received online. That way this stuff won't get lost forever. And while I'm at it, I've decided to put up a lot of the WC documents I downloaded from Howard Willens' site, which have been unavailable for quite some time now.

Edited May 23, 2016 by Tom Neal

[Sandy Larsen]

PAT SPEER, on 17 MAY 2016 at 03:48 A.M. said:

I've decided to go ahead and put some of the documents I received online. That way this stuff won't get lost forever. And while I'm at it, I've decided to put up a lot of the WC documents I downloaded from Howard Willens' site, which have been unavailable for quite some time now.

Edited May 23, 2016 by Sandy Larsen

[Tom Neal]

[Robert Prudhomme]

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.

[Robert Prudhomme]

Milo5

9/27/2009 4:44:45 AM EDT

A 158 semi wadcutter under 4.0 grains of 231 is an excellent .38 S&W load and usually shoots to point of aim with most S&W side eject revolvers.
DON'T use this load in older top breaks, it is a bit too warm for them.

In the right handgun such as the S&W and the Webley/Enfields, the .38 S&W isn't as weak as some people make it out to be.
Loads can be safely handloaded that approximate .38 Special ballistics.

Factory Commercial ammo is kept on the weak side to protect the older guns from damage.

I have had the pleasure of shooting original British made military 200 grain lead and 178 grain jacketed .38 S&W cartridges in both a Smith and Wesson
Victory model and a Webley.
I can assure you, these cartridges are not weak in power unless they were poorly stored.

Cogswell & Harrison used to convert old .38 S&W Victory revolvers to .38 Special for sale on the American surplus market.
The guns are now considered to be collectable curiosities that are unsafe to shoot.
Split cases, keyholed bullets on the target, flame eroded topstraps and cracked forcing cones were common issues with these conversions.

https://www.ar15.com/archive/topic.html?b=5&f=33&t=83171

[Tom Neal]

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...