1920s Manufacturing Process

[NobodyElse]

Hello,

I have two questions related to historical research I'm conducting:
1- Would "plunger" marks from one S&W .38 Revolver differ from other weapons of the same type?
2- Were all S&W .38 Revolvers made on the same machinery?

Thanks for your help,

RNS

 

[NobodyElse]

Hello,

I have two questions related to historical research I'm conducting:
1- Would "plunger" marks from one S&W .38 Revolver differ from other weapons of the same type?
2- Were all S&W .38 Revolvers made on the same machinery?

Thanks for your help,

RNS

 

[handejector]

RNS,
I don't know, but welcome to the forum.
The pics in this thread might be of value to you:
http://smith-wessonforum.com/eve/forums/a/tpc/f/5401039...491067251#5491067251

 

[Jellybean]

1) I'm not sure what you mean by "plunger marks" but any kind of tool marks or marks resulting from wear would change from one gun to the other.

2) Chances are no, they more than likely had multiple machinery to keep up with demand.

 

[mikepriwer]

I don't know what "plunger" means, either.

As to the machines: I toured the factory floor 6 years ago, and the big drop forge was
running that day. Its the first step in the operation, and pounds out the first
operation in producing the frames. The machine dates back to forever - maybe day 1 -
and is kicking out maybe 1 frame blank a minute. It takes two men to operate it, and
as far as I know, that is the only drop forge in the building. It is forgig red-hot
bar stock - the furnace sits right behind it. At one a minute, it could could easily
do 500 a day.

If you think about production, they made about 1,000,000 K-frames from 1900 to about
1940 - roughly. Over that 40 years, thats about 25,000 per year. Double that for
the N and I frames, and you have 50,000 guns a year, or something like 150 to 200 guns
per day, depending on 5 or 6 day workweeks. 200 guns per day is probably more than
they did, over that 40 year period.

I saw the broaching machine that rifled the barrels, and I'd feel comfortable in
saying that the machine could easily handly 200 barrels a day, so there was probably
only one of those.

The machining of those forged blanks, into semi-finished frames, is another story. I know
that now, they have rows and rows of CNC machinery processing the frames, but those
were not availalble back them. So, I would presume that they had multiple milling
machine stations going, all making the same frame. There is just no way that they
could have processed 200 frames a day on one machine. They probably had at least
10, maybe a lot more. On the other hand, I think there was only one roll-marking
machine, and also one serial-numbering machine for the frames.

So - I would say that, for some parts, they were all made on one machine - other parts
they were made on different machines. I know this is not factual, but the numbers give
you some idea of what must have been happening.

Later, Mike Priwer

 

[Ron H.]

Sir, S&W made .38 revolvers in several diferent frame sizes, so because of that alone, not all would have been made on the same machinery.

If by "plunger marks" you mean the indent left in the primer by the firing pin, I would think that these could certainly be specific to a particular gun, especially when viewed under a microscope or similar very strong magnification.

Hope this helps, and Semper Fi.

Ron H.

 

[digi-shots]

NE...

In reading your other posting, I think "plunger" refers to the firing pin.

The firing pin is the part of a gun that hits that back of the bullet shell casing (which ignites the primer which fires the bullet projectile).

This "hit" will put a small indentation on the fired shell. Each firing pin will have it's own "signature". In police forensics, a fired or spent bullet cartridge/casing can be matched up with the actual gun that fired it.

Here's a pic of an unfired .38 special bullet:

 

[mikepriwer]

Ron

Milling machines are milling machines - the operator sets them up to mill
whatever they want, that day. The drop forge has dies, so that one day it can
forge one thing, and another day, something else. The machines are not
specfic to a frame size - they are just machine tools. The broaches in the
rifler are replaceable - they would have different sizes for different
calibers, but only one machine. The same with all the equipment.

with todays CNC machines, with multi-tool tail stocks and tool rests, the
machine can be programed to mill a frame, eject it, take on some bar stock and
mill a barrel. Without human intervention. Hour after hour.

Later, Mike Priwer

 

[NobodyElse]

Thanks for the replies, and the photo of the bullet - would someone have similar pictures of fired bullets from that era showing the firing pin indentations?

Would the metal used in making the bullets and casings be consistent on a daily basis, and would that make a difference on the indentations?

I know some of these questions seem superfluous for this type of forum and that there are books out there dealing with this material. However, I don't want to assume that what applies to forensic analysis of bullets and casings now would automatically apply to bullets and weapons manufactured before 1930. I do appreciate the help you are giving me.

 

[delta-419]

One consideration is wear on the milling machines and dies. I was at Rock Island Arsenal when we converted to CNCs and wear over time produces varations that are within tolerances or not. Before the conversions, some of the machines dated to WWI.

 

[ImprovedModel56Fan]

Originally posted by NobodyElse:
Thanks for the replies, and the photo of the bullet - would someone have similar pictures of fired bullets from that era showing the firing pin indentations?

Bullets don't get indented by firing pins. Primers do. Bullet + primer + powder + cartridge case = cartridge.

Would the metal used in making the bullets and casings be consistent on a daily basis, and would that make a difference on the indentations?

Variation in metal used in making bullets and casings is invenereal to primer indentations. I don't know, but I strongly suspect that real-life variation in metal used to make primers also has nothing to do with identification of firearms by primer indentation.

I know some of these questions seem superfluous for this type of forum and that there are books out there dealing with this material.

Not superfluous, but elementary, and not the right questions.

However, I don't want to assume that what applies to forensic analysis of bullets and casings now would automatically apply to bullets and weapons manufactured before 1930.

Well, it may or may not. However, it would serve you much better to get an older book from the library about forensic ballistics than to try to get your answers from the internet, even from this forum.

I do appreciate the help you are giving me.

I, too, would be slightly suspicious about finding six empty cartridge cases on the ground in the aftermath of a cold-blooded killing, if that is what is alleged. Only slightly, however.

First, go to the library. Then, when you understand what was understood then, which was probably quite a bit about rifling marks and primer indentations, go look at the original evidence, if it is still around. If there is only testimony, from "expert witnesses," it may be quite a bit harder to get a feel for whether anything shady or sloppy was going on.

Good luck! Once you have everything, you might ought to post back here, or on a firearms-forensics website, if there is one.

 

[NobodyElse]

Thanks for clearing up the details for me on cartridges and variations in metal. I have checked the libraries for older books, but none I have seen give anything before the 1930s.

As I have said somewhere else, what are the right questions? I'm hoping someone will point me in the right direction because, unfortunately, I don't have time to do an exhaustive search on this issue given the number of other issues involved in this case, all of which I am subjecting to the scrutiny I'm trying to bring to the gun evidence.

If you think I am wasting the time of this forum, please let me know and I will desist, but I have found the answers here to be very useful.

Thanks again.

 

[digi-shots]

NE...

The image I posted was of a .38 special showing the rear end of shell casing. The "FC" stands for the Federal Cartrige company, and the "63" is the year of manufacturing, ie. 1963. The center portion is the "primer" and the portion that gets the indentation of the firing pin when fired.
Firing pins can wear overtime and may not make the same identical indent.

I don't think I have any older .38 special 1920's cartridges but I'll look around.

From what I've read so far of your postings, there is still a chance the gun could be one of a few different models. If you felt like spending $30 for a letter research from S&W, you could "guess" that it is a .38 M&P model 1905, and send the full serial number with your request. If it turns out the gun was shipped to Belknap, you would know for sure which model it is (since you know the gun in question WAS bought there). This is a "backwards" approach, but it might work.

Here's a pic of a S&W .38 special, M&P model 1905 that was shipped in 1924.
The serial number is 449,xxx which is a higher serial number than the one in question and a little newer. This will give you an idea of what the M&P model looks like.

 

[Ron H.]

Originally posted by mikepriwer:
Ron

Milling machines are milling machines - the operator sets them up to mill
whatever they want, that day. The drop forge has dies, so that one day it can
forge one thing, and another day, something else. The machines are not
specfic to a frame size - they are just machine tools. The broaches in the
rifler are replaceable - they would have different sizes for different
calibers, but only one machine. The same with all the equipment.

with todays CNC machines, with multi-tool tail stocks and tool rests, the
machine can be programed to mill a frame, eject it, take on some bar stock and
mill a barrel. Without human intervention. Hour after hour.

Later, Mike Priwer

Sir, that's all true, but we're not talking about today, we're talking about nearly 100 years ago.

In those days, if you needed to make large numbers of the same thing quickly, the way to do so was to use large numbers of relatively simple machines, each dedicated to a particular task: one drill press for this hole, one broach for that cut, etc. Changing machine setups before CNC was time-consuming and therefore expensive, so you wouldn't want to do it any more than necessary.

While it's possible that all hand ejectors may have been similar enough to be made on the same machines (though with different dies, jigs, and tooling), I'd still expect each frame size to have had its own dedicated line of machines after forging. Top-breaks almost certainly would have been finished on different machines than the hand ejectors simply because the two designs are so different.

Of course, it's all moot. In the context of the original poster's question (identifying a particular gun via machine marks left on a fired cartridge case), even tooling replacement for wear would produce different machining marks on the gun. Even if all the machines were the same (which seems unlikely to me), the tooling marks would still differ slightly from gun to gun, even of the same make and model.

Hope this helps, and Semper Fi.

Ron H.

 

[Driftwood Johnson]

Yes a milling machine is a milling machine. But how it is set up for production is often highly dependent on the size of the business and the fixturing used for any specific operation. At the time in question, for some operations, Smith used to have rows of milling machines and drill presses. Many of the individual machines were dedicated to one specific operation. They would be fixtured and tooled for that specific operation. One man often stood at his machine and did nothing but the exact same operation over and over again all day to dozens of frames. Once one operation was finished, the frames would be moved on to the next operation on another machine.

In the days before CNC equipment there were also pattern following millers to cut complex tool paths that could not be cut with conventional X Y tables. These machines needed a great deal of skill to operate as it was the skill of the operator turning the X and Y handles that kept the stylus of the machine pressed against the pattern as the work piece was cut. The presence of burrs and gouges on the floors of frame recesses were often the result of the difference in skill from one operator to another.

Modern computer controlled CNC equipment has done away with the need for pattern cutting, the computer generates the tool path at a consistant speed so that digs and gouges on the floor of the cut are virtually eliminated, as long as adequate lubrication is used, the tools are sharp, and the feed rate is not pushed too much. CNC milling machines can also do multiple operations that once required many separate machines to do. But most manufacturing facilities today, and I'm sure Smith is no different, still like to assign certain work tasks to certain machines. Sometimes because of fixturing requirements, sometimes just because it fits the work flow better.

Regarding the metal used to make cartridges and primers, not much has changed in the last 50 years or so. Probably longer.

Now.

If you are attempting to find evidence to present in a legal case, there are much better places than an open internet forum for that. Anybody, and I mean anybody, can write stuff here. There are many very knowledgeable contributors to this forum. There are other guys who have no idea what they're talking about. How are you going to distinguish between them?

 

[ImprovedModel56Fan]

Originally posted by Driftwood Johnson:
If you are attempting to find evidence to present in a legal case, there are much better places than an open internet forum for that. Anybody, and I mean anybody, can write stuff here. There are many very knowledgeable contributors to this forum. There are other guys who have no idea what they're talking about. How are you going to distinguish between them?

Worth repeating.

READ THE TESTIMONY. VIEW THE EVIDENCE. Do you have any reason to believe that the "experts" were wrong, or unfounded?

 

[cgt4570]

There was an archeological study done at the Little Big Horn battlefield a few years ago. All the empty .45-70 shell casings were excavated. Each indented primer was examined by microscope to determine individual rifles based on firing pin imprints. (They were all unique enough that even the untrained eye could differentiate the magnified pics.)
This way, they could trace the retreat path of each company of Custer's troopers. There was a very interesting History Channel documentary on this.

Chris

 

[mikepriwer]

I have two questions related to historical research I'm conducting:
1- Would "plunger" marks from one S&W .38 Revolver differ from other weapons of the same type?
2- Were all S&W .38 Revolvers made on the same machinery?

So - this is the question I was responding to. There was no mention of forensics, crime scene
analysis, cartridge shells, firing pins, etc. Since I admitted I didn't know what a plunger is,
I only responded to the second question.

I built my case around what I think the factory production was, at that time. Having read the
other responses, I think the right answer to that original 2nd question is

"Yes - they were all built on the same machinery. There were multiple machines involved, but
it was all the same machinery. "

We know, for a fact, that the machining capability exceeded the gun production by a significant
amount. We know this, because all the parts were made in batches, starting with the frames.
Clearly they had an inventory of frames, and as those were used, they made up another batch.
As an aside, this is the primary reason that guns were shipped out of serial number order.
This was true for all the guns that they made. This has been written about extensively. This
is why I think that the same milling machines were used for different gun lines: when sufficient
inventory of one part was built up, they switched the machine(s) over to another part. Otherwise,
half the factory would have perpetually sat idle, and we know that was not the case.

Now - maybe this was not the right question to have been asked - but that is what it was.

Later, Mike Priwer

 

[walnutred]

Maybe if you would tell us what plot detail you are trying to validate in the book you are writing it would help us answer your questions. You will also find that allowing us to provide you with the correct terminology might help your writing process.

As I recall an insurance salesman did quite well with a book about submarines partially because he took the time to get the terminology right. I suspect Tom Clancy has not peddled insurance for some time now

 

[Guest]

Originally posted by NobodyElse:
Hello,

I have two questions related to historical research I'm conducting:
1- Would "plunger" marks from one S&W .38 Revolver differ from other weapons of the same type?
2- Were all S&W .38 Revolvers made on the same machinery?

Thanks for your help,

RNS

Well, from reading your several Postings it would appear that you have a question about the appearance of fired shell casings. The simple answer is that six cases from a single cylinder of any six shot .38 caliber revolver will ALL be slightly different. The next six shell casings from the same revolver will be similar but still slightly different depending upon many factors. MAK