Why did it do this?

[Alpo]

I have a 1937 Brazilian. Twice it has fired when I did not want it to.

Once, I came home and placed it on a shelf. While the shelf was plenty wide enough for a naked K-frame, it was apparently not wide enough for a holstered N-frame, and I got six or eight steps away when I heard a WHAP, turned and saw it on the floor. Maybe the vibration of my walking on the wooden floor gave it the little bit of impulse to fall. Just about the time I was thinking, "Damn, good thing it did not go off", I smelled the burnt powder. Holster acted like a silencer.

Fortunately, between Speer Flying Ashtrays, and solid wood door, I did not kill the little old lady across the street.





But why did it shoot? I thought Smith had a hammer block to prevent that.

Some years later my thumb slipped as I was cocking it, and again it went bang without my permission. My finger was not on the trigger, so why did it shoot?

Again, I thought Smiths were not supposed to do that.

The "Smith and Wesson Expert" at the range said it was probably a bad rebound slide spring, sold me a Wolfe spring kit, and replaced both the rebound and the main spring for me.

Since then I have not had a recurrence, but then, I have also not had my thumb slip from the hammer nor dropped it six feet to a wood floor.

Does it sound like the problem could have been the rebound spring?

What, exactly, does the rebound spring and slide do?

 

[pharmer]

If I'm not mistaken, the improved hammer block safety came along around WWII. Might be the cause. Joe

 

[gunnails]

S&W changed the safety bar(?) about the start of the 2nd world war(?)
because when dropped on the hammer the M&P could fire, killed a sailor I think.

When was your Gat manufactured.

 

[Grayfox]

Yep, no hammer block. Most any S&W revolver made prior to WW II can go off if dropped or you let the hammer slip.

 

[Alpo]

S&W changed the safety bar(?) about the start of the 2nd world war(?)
because when dropped on the hammer the M&P could fire, killed a sailor I think.

When was your Gat manufactured.

Being it is a 1937 Brazilian, I'm guessing 1937.

 

[JP@AK]

S&W changed the safety bar(?) about the start of the 2nd world war(?)

The change to the new sliding hammer block safety was implemented in December, 1944. The first example shipped in January, 1945.

 

[gunnails]

Being it is a 1937 Brazilian, I'm guessing 1937.

===========================

LOL, my bad, short term memory loss and all that.

 

[wheelgun610]

Sounds to me like maybe someone tried doing a shade tree action job on that gun and went a little too far in stoning the sear engagement surface on the trigger.

With the gun unloaded, cock the hammer then see if you can push it off with your thumb (finger off the trigger). If so, you may need to replace the trigger, hammer - or both to prevent those types of accidental discharges.

Under no circumstance would I leave that gun loaded....

Mark

 

[L Pete]

People just don't understand.

Those old Smith made prior to the safety bar are only safe to carry with five rounds and the hammer on any empty chamber, a la Colt Peacemaker. What happened to you is the cause of the safety bar, and if the hammer was struck or landed on with a round under it, an AD happened. During WWII, there were too many accidents in combat situations, and Smith & Wesson, redesigned the lock with the safety bar, as witnessed by the change of the V to an S in the serial sequence of the M & Ps.

Incidentally, all the old time cops knew this, hence, their service revolvers were carried only with five rounds. I'm old enough that I knew some of those old time cops, and even with modern revolvers with the safety bar, they still refused to load six. (Old habits are hard to break.)

If you carry one of these older revolvers, always, repeat always, carry only five rounds in the chambers with the sixth empty chamber under the hammer. It might cost you your life if you load that sixth chamber.

 

[Hondo44]

The 1937 style hammer block safety can be seen retreating from the top, right side of the hammer channel, as the hammer is pulled back. And re-entering the channel as the hammer is lowered.

In the case of the sailor killed during the war, the hammer block was either gummed up and did not return under the hammer or the force of the gun striking the ship deck on the hammer after a fall of ~ 80 feet, over powered the safety block tension spring. That's why that style safety was deemed NOT fool proof, hence the new style sliding bar safety retrofitted in Victory model .38s and introduced after the war on all S&W hand ejector revolvers.

To test the safety at the range, load the gun, cock the hammer, then while holding the hammer pull the trigger to uncock the hammer, release the trigger and let the hammer drop. It should not discharge.

If it discharges, try again, but this time after un-cocking the hammer, push the trigger forward and keep pressure on it with your off hand. Now let hammer drop. If it does not discharge, the trigger rebound spring is the problem.

 

[Morgan88]

Hi guys
You are making me a little nervous. I have a 1920 ish S&W M&P. Does it fall into your category of no hammer block safety. It was sent back the factory in 1951 for a new barrel and refinish. Don't know if that is relevant. I tried cocking it and pushing on the hammer trying to get it to release errantly and it wouldn't. Set my mind at ease or put it away?

 

[H Richard]

With the gun unloaded, cock the hammer back ans look down into the space between the hammer and the action. If there is a hammer block there it will be visible.

 

[lebomm]

Morgan88;
The older guns do have a hammer block, but it's just a hump on the rebound slide contacting the toe of the hammer, and not nearly so robust as the 1945 installation. It's what causes the hammer to rebound when the trigger is released. Some of them have a hammer block in the sideplate that's operated by the hand - that one's better, but still not as positive as the sliding block we still see today.
Try the "push-off" trick on the range with finger off trigger. Gun should not fire. If you're comfortable pulling the sideplate, the block looks like a V-spring mounted in the sideplate, and the hand has a "fin" down its back, and still has the hammer-toe hump on the rebound slide. As long as all parts are in good condition, your revolver should be gtg. Keep us posted.

Larry

 

[DWalt]

Hi guys
You are making me a little nervous. I have a 1920 ish S&W M&P. Does it fall into your category of no hammer block safety. It was sent back the factory in 1951 for a new barrel and refinish. Don't know if that is relevant. I tried cocking it and pushing on the hammer trying to get it to release errantly and it wouldn't. Set my mind at ease or put it away?

Conversion of any pre-1945 revolver to use the improved hammer block safety is unlikely, as it was not simply a matter of swapping parts. It involved some intricate machining, additional parts, and was expensive to perform. But a few earlier Victory models did in fact receive such a retrofit. The older hammer lock mechanism protected against accidental discharge as a result of dropping the revolver on the hammer, and I doubt that there was a significant number of those mishaps known. I don't think anyone has a clear idea of exactly what happened in the famous (and possibly singular) Navy drop fatality incident, but it obviously had some extraordinary cause, and was an exception rather than the rule. In any event, the 1945 design improvement added an additional layer of reliability to the older hammer blocking safety design. The use of positive hammer blocking safety devices on revolvers goes back a very long time.

 

[old bear]

When was your Gat manufactured.

Gat. What in the hell is a gat ? Is that something like a "rosco, or a rod?

 

[DWalt]

Gat. What in the hell is a gat ? Is that something like a "rosco, or a rod?

Same as a heater.

 

[gunnails]

Gat. What in the hell is a gat ? Is that something like a "rosco, or a rod?

=======================

I use to watch a lot of old movies with Dad when I was a kid.

Via the urban dictionary.

-----------------------------------------------

Old slang, meaning gun. Came from shortening Gattling gun to just gat. Was used during the prohibition era to name any gun, but specifically the thompson submachine gun, aka The Tommy Gun.
Just get that gat out of my face, and everything will be jake.

 

[handejector]

Does your Brazilian have a flat top frame, or is it a round top?
Bright Blue, or Satin?

 

[Geno44]

My late Grandfather lived in Suburban Chicago in the 1950's and used to carry his S&W .32 break-top in the jacket he wore when walking his dog at night. One night he was putting on his jacket and the gun fell out of the pocket and it hit the floor and fired. The bullet went into the wall about 8" to one side of his not very mechanical head. He should have only loaded 4. He passed away at 84 some 12 years later. (He was a real nice guy!)

 

[Hondo44]

After checking my notes, I didn't entirely recall correctly the facts around the Navy death in post #10.

Both the 1st (the hump on the rebound slide contacting the hump on the hammer toe) and the 2nd style (in the sideplate) failed in the Navy fatality during WW II when a K38 was dropped, also shearing the hammer pivot pin.

The problem with the hand activated stop is that it is only positive in one direction, and that is when it is moved out of the way of the hammer by the hand. When it returns to a blocking position, it is moved only by the spring behind it. Thus, if cosmoline, rust or gunk, was restricting this, it would not return to the blocking position in front of the hammer nose.

I don't know exactly when the 2nd style hand operated hammer block was added to the K frame service revolvers, but it was reportedly around 1918, however the target revolvers didn't get it until the mid 1920's.


2nd style hammer block in sideplate, visible in top right side of hammer channel:

 

[k22fan]

A high percentage of Brazilian Model 1937s were built on left over WW I frames and consequently lack the pre-WWII hammer block Hondo44 showed us a picture of. These early frames have the round top strap with a tiny U notch sight. 1937s built on new frames have flat top top straps with an easier to see square notch sight. Only the newly built frames got the hammer block that was pushed out of the hammer’s way by the hand then returned by a spring. That’s why handejector asked about Alpo’s top strap.

A fully forward rebound slide positions a flat surface beneath the hammer toe obstructing hammer rotation. That will prevent discharges from landing on the hammer unless the hammer pivot pin shears off or the hammer toe shears off. I can imagine the pivot pin shearing off at the end of an 80 foot fall onto a steel deck but that’s and extreme impact on the hammer spur. Either breakage would have prevented further use of the revolver so neither happened to Alpo.

If you install too weak a rebound spring in the quest for a light trigger pull the rebound system will not reliably reset. I think Alpo’s rangemaster was correct. His rebound slide was not forward to stop his hammer rotating. If that was the case his trigger also was not pushed forward so his hand was at least part way up. Thus, if he even has the old hammer block the hand would have held it partially or completely retracted.

The modern rebound slide actuated hammer block should prevent a discharge from a blow on the hammer that shears the hammer pivot pin but like the pre-WWII hammer block it will not prevent a discharge if the rebound slide does not return. That’s one more reason to use a stiff enough rebound spring to have a snappy trigger return.

 

[paul s]

I would retire that old gun and get something newer and safer. Next time may not be so lucky?

 

[JSR III]

My wife told me last week that she was going out to get a Brazilian. Imagine my disapointment when she didn't bring me home another S&W as I had expected.

 

[k22fan]

I would retire that old gun and get something newer and safer. Next time may not be so lucky?

Absolutely! Send it straight to me to fire a bucket of reloads through ... oops, I mean for safe disposal.

 

[DWalt]

"I don't know exactly when the 2A style hand operated hammer block was added to the K frame service revolvers, but it was reportedly around 1918, however the target revolvers didn't get it until the mid 1920's."

Supposedly there was a new K-frame hammer block incorporated at SN 497509 on 7/24/1925. Was that for the target revolvers only? Or all K-frames?

 

[Hondo44]

I would retire that old gun and get something newer and safer. Next time may not be so lucky?

Even something newer and safer can malfunction. Sounds like he's already fixed it. And if he performs the tests outlined above it'll be confirmed.

 

[Alpo]

Don't know about the top strap. Ain't sure which safe it is in.

As for color, Navy Arms parkerized it before they sold it to me.

SN is 200579, though, if that helps any.

 

[handejector]

I'm not convinced it is fixed.
Where is our OP?

Question-
What ammo was in the gun when it drop-fired?
Factory or reloads?
If you still have any of that ammo, what is the primer depth like?
Near Flush?
IF reloads, any chance of a high primer?

Next-
Open the cylinder and empty the gun if loaded.
Any burrs around the firing pin hole?
Does the firing pin protrude at all from the recoil shield?
PUSH the hammer with your thumb- does it protrude now? Does the hammer have any wiggle?
Any chance the hammer stud is broken?
Believe it or not, a hammer stud can break a little below flush with the frame. Then, occasionally, the ends of the stud will stay more or less in place in the recess created in the frame where it broke and its hole in the sideplate. I have actually seen an S&W with a broken hammer stud that would function and shoot. But, the firing pin also protruded slightly thru the recoil shield if you pushed the hammer hard.


So,
I'm wondering if we had a "slam-fire".
High primer + burrs on recoil shield.
OR
Protruding firing pin.
OR
High primer slamming into recoil shield. If the ammo was mooned together, there could have been a lot of weight involved.

 

[k22fan]

IIRC the 200,xxx s/n makes this a WWI frame without the early hammer block. It also means that, unlike newer S&Ws that have a staked in hammer pivot pin or stud as hand ejector called it, its stud is a screwed in part. That makes it easier to replace.

I must admit I assumed a revolver would not continue to function with a broken hammer stud. It is past time to tap up the side plate, remove the hammer, and pull on that stud.

 

[Alpo]

I know it was clipped. Full moons are all I use. Might have been reloads, but I'm pretty sure it was factory. Been more than ten years, so memory is a little spotty.