Smith & Wesson hammer block

Risk of having the hammer axle pin break with a hard drop of a heavy revolver directly onto the hammer seems possible enough to make the hammer block worth it...

On a side note, the current production internal hammer revolvers like the Model 642 do not have a hammer block, they rely solely on the rebound slide... since such a super hard blow is impossible.

According to the SCSW 4th Edition, the original hammer block safety was a shoulder on the rebound slide forced against a shoulder on the hammer.

The new (and current) design was introduced in September of 1944 after the shipboard incident mentioned above.

The fatality by accidental discharge of a Smith & Wesson revolver on a US Navy warship during the Second World War is an actual incident. I believe that Charles W. Pate discusses the changes resulting from this incident and reproduces contemporary documents regarding it in his book "United States Handguns of World War II: The Secondary Pistols and Revolvers", by which he means everything except the Model 1911. This is it on Amazon: https://www.amazon.com/U-S-Handguns-World-War-II/dp/0917218752

I do not have the book here at my computer, or I would supply specifics here.

The relevant section in the Pate book is pages 333 to 345. He does not name the sailor who was killed, or the exact date the accident happened, but the sequence of paperwork starts with a Navy memo of May 6, 1944.

Pate includes an interesting report on tests on the type of Smith & Wesson revolver involved in the accident, S&Ws with new style safety adopted as a result of the accident, and Colt Commando revolvers, where the hammers on the guns were stuck with a series of blows to see if and when the safety mechanisms could be defeated and a primer detonated. Both the old style S&W and the Commando could eventually be fired that way; on the new style S&W, the pistols' hammers broke before the gun fired.

My recollection of the accident from somewhere is that a pilot or aircrewman was leaving an airplane after landing on a aircraft carrier and his revolver fell out of his shoulder holster and fired. The decks of US aircraft carriers were all planked with wood at that time, BTW. The trigger mechanism of the revolver was found to be so choked with grease that the safety mechanism did not function correctly. I think the part involved was called the "rebound slide".

Howdy

I post regularly on Facebook, although I do not post much about firearms. I am not surprised people on Facebook don't know very much about firearms.

Yes, the incident where a sailor was killed when a S&W revolver fell to the deck of a warship in WWII is very real, it is not a myth. I must say the description Monac gave is the most complete description of the incident I have ever heard. Before that, I did not know what type of warship was involved, nor how far the revolver fell in order to discharge. If a pilot was climbing of the wing of his plane on the deck of a carrier, it is possible the revolver could have fallen 8 or 10 feet before hitting the deck.

There were three different styles of hammer blocks S&W installed in their swing out cylinder revolvers over the years.

The very earliest S&W Hand Ejectors had no hammer blocks at all. Yes, the hammer of all S&W revolvers rebounds. This photo shows how the bump on top of the Rebound Slide wedges the hammer back and pulls the hammer (and firing pin) back away from the frame. However, this was far from fail safe. The Rebound Slide is hollow. It houses the Rebound Slide Spring inside. Given enough force on the hammer spur, the Rebound Slide could be crushed, or the section at the bottom of the hammer could shear off, allowing the firing pin to move forward and fire a live round under the hammer.






Clearly S&W felt the need for a hammer block, or they would not have started installing them. This is the first type of hammer block S&W installed in their revolvers. I do not have an exact date of when S&W began installing hammer blocks, but this one is from an old 38 Military and Police that shipped in 1920. The hammer block resides in a slot in the side plate. It is made of spring steel and is peened to the side plate at its bottom. The rectangular tab at the top of the hammer block extends toward us in this photo. I have positioned the hand of the revolver in the recess for it in the side plate. Normally the tab at the top sits between the hammer and the frame. There is a small tapered pin sitting in a hole in the side plate. When the hammer is cocked, either in double action or single action, the sloping side of the hand pushes the small pin and it retracts the hammer block down into its slot in the frame, clearing the way for the hammer to fall all the way and fire a cartridge.






This is the second type of hammer block that S&W put inside their revolvers for many years. This one is in a 38 M&P that left the factory in 1939. This is the type of hammer block that failed in the incident where the sailor was killed in WWII. This style of hammer block is simpler and has less parts than the earlier style. The hammer block is still made from spring steel and it is still peened to the side plate, and it still resides in a slot in the side plate. Again, like the earlier type it is normally sitting with the rectangular extension at the top extending between the hammer and the frame. Notice there is a ramp on the rear side of the hand. When the hand rises, either in double action or single action, the ramp engages the small tab on the side of the hammer block. This retracts the hammer block down into its slot in the side frame, clearing the way for the hammer to fall all the way and fire a cartridge.






After the shipboard incident where the sailor was killed, it was determined that cosmoline, which had been installed in the revolver prior to shipping, had not been properly cleaned away before the revolver in question was issued. The cosmoline had retained the hammer block in the retracted position, against its spring force, allowing the revolver in question to fire when the hammer spur struck the deck of the war ship. Yes, in order for this to happen, either the hollow Rebound Slide would have been crushed, or the thin section at the bottom of the hammer would have sheared off, allowing the firing pin to strike a cartridge with enough force to fire a cartridge.

Smith and Wesson had a large contract at the time to supply revolvers to the Army. The Army threatened to cancel the contract unless S&W came up with a fix. S&W set up test stands and determined that it was indeed possible for revolvers using the current style of hammer block to discharge when dropped under the right conditions.The engineers at S&W were called in and within a week the design of the new style hammer block was ready for production. Victory Revolvers in the field were recalled and the new style hammer block was installed. Victory Models still in production, which normally had a V for victory prefix in the serial number, were given a SV prefix.

This is the new style (or current style) of hammer block. It is a simple stamped piece and the end has been twisted vertically to form the tab that sits between the hammer and the frame.






This photo shows how the new style hammer block rests in a slot in the side plate. Unlike the older versions, this style of hammer block is not pinned in place but is free to slide up and down in its slot.






I have placed the hammer block in place in this 44 Hand Ejector, 4th Model. It is sitting in the position it normally sits in in the lockwork. Notice even though the hammer block is between the hammer and the frame, the hammer is not actually touching the hammer block, there is a little bit of space. The hammer block is actuated by the pin in the Rebound Slide. When the Rebound Slide moves back as the hammer is cocked, the pin withdraws the hammer block down, freeing the hammer to fall all the way.

halfmoonclip said:

But if it was stuck, the trigger would have been to the rear as well; the rebound slide spring is what powers the trigger.

Click to expand...

Study my first photo. As you can see, the rebound slide is forward and the hammer is down. This is the condition in which an accidental discharge could occur. If enough force was presented to the hammer spur, the hammer could be driven forward with enough force to either crush the hollow Rebound Slide, or shear off the bottom of the hammer, either situation could drive the hammer forward forcefully enough to fire a cartridge under the hammer.

I am not saying an old non-hammer block equipped S&W revolver is as dangerous to carry fully loaded as an old style Colt Single Action revolver. The parts in a Colt were very different, and they were much more fragile than the parts inside a S&W revolver. Assuredly, many police officers carried old non-hammer block equipped S&W revolvers fully loaded for many years without incident. But the possibility was always there. Why else would S&W have gone to the extra expense of installing hammer blocks?

As I said, S&W conducted tests after the 1944 incident and found that it was indeed possible for a drop from waist high to crush the internal parts enough for the revolver to fire.

Yes, the modern hammer block is entirely dependent on the Rebound Slide spring to keep everything functioning properly. But it is a very strong spring. Have you ever tried to reinstall one? A very strong spring, completely up to the job S&W added to its tasks back in 1944.

The Colt Positive Safety hammer block was introduced 1905-1908 in the various models. It is more certain of action than S&W "flag" blocks.

The Iver Johnson Safety Automatic revolvers of 1894 introduced the transfer bar now used in Rugers and Colts.

The S&W Centennial "hammerless" revolvers do not have a hammer block, there is no exposed hammer to whack.

This 2013 thread at the S&W Collectors Forum:

http://smith-wessonforum.com/s-w-hand-ejectors-1896-1961/346346-help-history-hammer-block.html

has a variety of different accounts of the 1944 accident. However, post #8 by shawn mccarver says: "The incident, along with excerpts from government reports and S&W's side of the story are well-documented in the new [in 2013] book on the K frame by T. J. Mullin. The book is just out and available from Collector Grade Publications."

I've never read that book. Does anyone here have it?

Meanwhile, I am going to go through my clipping file and other books to see if I can verify my memory regarding this incident. I don't want to perpetuate unsubstantiated claims. SOMETHING certainly happened, and someone in the US Navy was killed, but I want to find a reliable account of how.

As I said, I do not know exactly when S&W began putting hammer blocks in their revolvers.

This the very first revolver S&W made with a side swinging cylinder, a 32 Hand Ejector, 1st Model, also known as the Model of 1896 for the year it was introduced. This one shipped in 1898. Notice the mechanism is quite different from a modern S&W, there is no rebound slide. There is also no hammer block.






This is a 38 Hand Ejector 1st Model, also known as the Model of 1899. This was the very first revolver S&W made for the then brand new 38 Special cartridge. This one shipped in October of 1899. You can see that the mechanism of this revolver is also quite different than any later S&W revolvers; like the Model of 1896 there is no rebound slide. You will also notice there is no hammer block.






This nickel plated Triple Lock left the factory in 1915. It has no hammer block.






A Model1917 that shipped in 1918. No hammer block.






A K-22 Outdoorsman from 1935. No hammer block.





I have lots of other early S&W revolvers that have no hammer block, I just do not have any photos of their interiors.

My point is, the oldest S&W revolver I have with a hammer block is this 38 Military and Police that shipped in 1920. You can see the 1st style hammer block mounted in the side plate. So clearly S&W phased in hammer blocks on different models at different times, since the K-22 I pictured left the factory in 1935.






You may have noticed the shape of the parts varied over the years. This is a closeup of that 1920 38 M&P. Notice how thin the metal is at the bottom of the hammer and tell me you think it would take a great deal of force to shear off the bottom of the hammer, allowing the revolver to fire if the hammer were to be struck with a heavy blow.






This is a Victory Model, the exact model we have been talking about that killed the sailor in 1944. Notice the 2nd type of hammer block in the side plate.






This is the 38 M&P I posted earlier that left the factory in 1939. The exact same set up as the Victory Model of a few years later. The same hammer block, and the same configuration of the rebound slide and hammer as in the Victory Model. Take a close look at how thin the metal is at the bottom of the hammer and tell me again how it would require an "almighty hard blow" to break it.






Remain as skeptical as you want, S&W conducted tests in 1944 simulating revolvers dropped from waist high and many of them failed the drop test.

Yes, it was Cosmoline inside the Victory Model in 1944 that prevented the 2nd style hammer block from functioning properly, killing a sailor when it struck the deck.

And if S&W began putting hammer blocks inside their revolvers as early as 1920, when there were no large government contracts at risk, exactly what was the reason, other than they realized their revolvers without hammer blocks inside were not safe to carry fully loaded?

Again, I reiterate that thousands of early S&W revolvers without hammer blocks inside were carried for many years without incident. Again, I will tell you that the parts inside these early S&W revolvers were more robust than the parts inside a Colt Single Action Army revolver.

These are Colt parts. Notice the so called 'safety cock' notch the upper arrow is pointing to. Now notice how thin the sear on the trigger is that the lower arrow is pointing to. This is why anyone who is familiar with a Colt knows to never carry it fully loaded with the hammer on the 'safety cock' notch. Drop that puppy on the floor on its hammer and it is almost guaranteed the sear will break off and the revolver will fire.






As I keep saying, the parts inside an early S&W revolver were more robust than the parts inside a SAA. Drop the Colt on its hammer and it is almost guaranteed to fire. As a matter of fact, drop the stirrup of your saddle on the hammer while you are mounting your horse, and you will probably have the bullet graze your leg. Drop the S&W and chances are you will be OK.

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The "hammer axle"???? That's hilarious......