Empty Chamber Safety Question

[XD Fan]

Also like the original, there is no trasfer bar safety, so it should be carried with an empty chamber under the hammer

I am a relative newcomer to revolvers, and I am wondering about safe carry with a round under the hammer. What precisely is a transfer bar safety and how do I know if my revolver has one. It is a Taurus Model 94 .22. It is double action and I feel fairly certain that it is safe to carry with a round in the chamber, but I am basing that on assumptions and educated guess. I would appreciate a little help.

 

[Vern Humphrey]

I am a relative newcomer to revolvers, and I am wondering about safe carry with a round under the hammer. What precisely is a transfer bar safety and how do I know if my revolver has one. It is a Taurus Model 94 .22.

I can't think offhand of any modern revolver design that is unsafe with a round under the hammer.

The Colt SAA and some clones rely on a half-cock for safety. This is a notch in the tumbler with an undercut. When the hammer is at half-cock, you cannot pull the trigger, and the firing pin is held off the primer. To fire, you must pull the hammer back to the full cock notch.

However, the parts involved (the nose of the sear and the undercut of the half cock) are small and fragile. A sharp blow on the hammer will break them and cause the gun to fire. The classic SAA accident was when a man was saddling a horse. He would throw the stirrup up in the seat of the saddle to tighten the girth. If the horse moved, the stirrup could fall and hit the hammer, and bang!

Modern revolvers have two different kinds of safety -- the oldest is the rebounding hammer. If you take the empty revolver, pull the trigger and slowly release it, youi can see the hammer move back as the trigger is released. The mechanism that does that is much more sturdy than the old half cock.

The more modern method is the transfer bar. The firing pin is mounted in the frame, not on the face of the hammer. The hammer face is shaped like an upside-down L. The foot of the L rests on the frame when the hammer is down, and the base of the firing pin is below that point. The hammer cannot contact the firing pin.

When the gun is fired, pressure on the trigger moves a bar up to cover the end of the firing pin. When the hammer falls, it transfers its energy to this bar, which in turn transfers it to the firing pin.

 

[Miamitiger]

Vern Humphrey:Thanks very much! This is the type of answer that the new member appreciate. I am very glad that there are some experts here!!!

 

[Vern Humphrey]

De nada.

 

[XD Fan]

Awesome information Vern Humphrey! Thanks!

 

[Jim March]

Later model Taurii will have transfer bars, similar to all post-1973 Rugers (SA and DA), the later S&Ws, Charter Arms (all) and many others.

Earlier Taurus models will have hammer-block safeties, similar to S&W's post-WW2 design going forward to...huh...when DID they switch? Across the late '80s through '90s I think.

Anyways. If the firing pin is mounted on the hammer, it's probably a hammer-block gun.

With this setup, a piece of metal moves up and in the way of the hammer's fall, unless a deliberate trigger pull moves the metal bar out of the way.

If the hammer block breaks, the gun becomes as "zero safety" as an 1873 Colt, if not worse (not even a half-cock safety, as unreliable as that was). (Unless the broken bit of metal gets down in the "innards" and ties the gun up solid, which isn't that unlikely...)

If a transfer bar breaks, the gun becomes a doorstop - utterly unable to go off.

The transfer bar is considered just slightly safer, but the safety difference is miniscule as long as both are well designed. S&W hammer-blocks from WW2 and prior were just a bit "iffy" and a revision was made due to a drop-fire accident that was well published during the war. Pre-war Colts had a better hammer-block system than S&W.

The hammer block has an interesting advantage: because the linkage between hammer and firing pin is more direct, the mainspring can be up to 25% lighter than the spring in an otherwise similar transfer bar gun.

I would not select a gun purely on the basis of which safety it had, so long as the safety was working and of a known respectable type. A reasonably late-model Taurus with hammer block would fall into that category as long as the gun itself is sound. Early Taurus models imported by other companies (other importer's marks present) would indicate the gun is of very early vintage and quality was "iffy" bordering on Godawful.

-----

The "revolver checkout process" (see link and extensive, nay, exhaustive comments stickied this forum) includes a procedure for making sure the firing pin is retracting when you release trigger pressure, which in turn is a sure sign that either a hammer block or transfer bar is in good working order.

 

[XD Fan]

Thanks, Jim!

 

[Confederate]

Once you see a hammer block in one revolver, you can generally see it in others. As a surefire test, take the unloaded revolver and cock and pull the hammer. With your finger still depressing the trigger, hold it up to a light until you can see the firing pin sticking through. Then release the trigger. If the firing pin retracts, you've got a hammer block. If it remains, it doesn't.

Here's a picture of the hammer block in a Ruger Speed-Six:



Ruger makes all its parts oversize, but the bar looks roughly the same, perhaps a bit smaller.

 

[Jim March]

That is NOT a hammer block. It's a transfer bar.

Look at the pic again: with the trigger pulled, that piece of metal the red arrow is pointing to will come UP and sit on top of the firing pin. The hammer can then hit it. Look at the face of the hammer in this pic: there is a "step" that hits the frame above the firing pin. When the transfer bar is retracted (no pressure on trigger) that "step" will block the rest of the hammer below that step from hitting the firing pin. When cocked the trigger will be rearwards and the firing pin up and ready to make bang, but as the hammer falls the trigger will go forward and retract the transfer bar. If you pull the trigger to fire, the transfer bar will rise a little bit more from where it's at in this pic.

This "tip" will help you understand the gun better:

Let's say you were deep in the woods and you broke the transfer bar off. Your gun is now a doorstop. Say you manage to shake loose the broken end of the transfer bar. Your only tool is a file. You can shave off that "step" and render the hammer face completely flat, which in turn would make the gun safe for five-up carry only. Which would at least get you a gun fit for a wilderness survival situation until you can score a new hammer off Brownell's .

----

On a hammer-block gun, the hammer block moves DOWN when the trigger is pulled, not up. In it's upward position it prevents a full forward movement of the hammer. A transfer bar doesn't impede the hammer at all, it simply renders the hammer useless as far as hitting the firing pin is concerned. Only the combined hammer and transfer bar *jointly* can hit the firing pin.

----

There are a couple of transfer bar designs where the transfer bar is built into the front face of the hammer itself, and is hard to see until you look at the hammer face. Rugers don't use this, only the Beretta Stampede and Freedom Arms '97 frames that I know of do this. It still works the same way as other transfer bars, same level of safety.

With the Ruger-type transfer bar, something has to push the transfer bar rearwards as it moves up, otherwise it could slam into the firing pin's side and tie the gun up. On a Ruger single action revolver, the "base pin" (the "axle" that the cylinder rotates on) has a spring-loaded tip as it goes into the back of the frame. That's what pushes the transfer bar backwards. If you remove the cylinder and base pin from a Ruger SA, the action will still work as long as the barrel is tilted upwards, letting gravity drag the transfer bar back. If you try it horizontal or muzzle-down, whoops. Every once in a while (VERY rare!) the spring-loaded tip can get clogged up. If you ever have a Ruger "tie up on you" on cocking, back off, point it to the sky and try again. The cure is a new base pin as the small "poker" and small spring are "tacked" into the end of the base pin.

Whenever you have the cylinder out of the Ruger, check the end of the pin for "springiness" or any sign of it being sticky. Buy a Belt Mountain base pin if it's at all a concern. Again: your odds of running into this are ridiculously low.

This failure mode is impossible with the transfer bars integrated in the hammer face.

 

[fallingblock]

Thanks for the in-depth discussion, Jim...

With the Ruger-type transfer bar, something has to push the transfer bar rearwards as it moves up, otherwise it could slam into the firing pin's side and tie the gun up. On a Ruger single action revolver, the "base pin" (the "axle" that the cylinder rotates on) has a spring-loaded tip as it goes into the back of the frame. That's what pushes the transfer bar backwards.

What part pushes the transfer bar rearward in the double action Ruger?

 

[Jim March]

The end ("middle") of the ejector star, I *think*. Not 100% sure though.

 

[Retro]

How frequently do you see a breakage of this transfer bar due to repeated use and or dry-firing in a Ruger or Taurus?

 

[Jim March]

Not often.

I've heard more reports of breakage of transfer bars in Ruger SAs than any other gun type, BUT those reports are on the SASSNET forums where guys shoot enormous amounts in competition.

Ruger SAs get used in SASS competition probably more than any other type, and the duty cycles are just tremendous in some cases. The real competitors are all reloading and can put 50,000 rounds on a gun in a year, two tops. Those guys break every other gun type too . The guys running Italian guns usually buy three - one as either spare or "undergoing repairs" on a fairly frequent basis.

My read is, as long as the gun has a Belt Mountain or other set-screw base pin in place, and blue locktight on grip frame and ejector rod screws, a Ruger SA will keep running long after anything else is dead and buried. If a Ruger DOES break, the transfer bar is a weak point. Some guys are swapping them every 10,000 rounds or so as a matter of course, as it's a cheap part that doesn't need precision fitting (read: always a drop-in). Or they'll just keep an extra and a screwdriver handy...at any given major match, several people will have them and begging an extra ain't a big thing.

Your odds of having one fail in a streetfight on a CCW gun is pretty damned small.

 

[Retro]

Thanks, Jim, for the info.

 

[fallingblock]

Yes, thanks Jim...

I finally had time to dig a GP100 out of the safe and study what powers the transfer bar away from the frame mounted firing pin's head.

Indeed, it is the "center pin lock" (KE 53) powered by the "center pin spring"
(KTO3400) that presses the "crane latch" (KT00900) into the transfer bar.

You can observe this by unlatching and swinging out the cylinder and then, while holding the crane latch forward, slowly cock the hammer while watching the transfer bar.

I know, it was easier to ask.

 

[Confederate]

That is NOT a hammer block. It's a transfer bar.

Quite right, my mistake. The transfer bar is necessary for the hammer to "transfer" the energy to the firing pin. Hammer blocks "block" the hammer's energy to the firing pin. Ruger's transfer bar is fundamentally different from Smith & Wesson's hammer block:



The gun is in the uncocked position. The bar prevents the firing pin from touching the primer. The Interarms' Virginia Dragoon had a hammer block activated from just forward of the cylinder. Once the gun was loaded, the bar could be moved backward to physically block the hammer.

Let's say you were deep in the woods and you broke the transfer bar off. Your gun is now a doorstop.

This is true, but the liklihood of it ever happening to a Ruger is not as great as having the Smith & Wesson's hammer block bar break. I once had a stainless hammer fracture like glass because of faulty heat treatment. But most of these breakages occur early in the life of the gun. Although I've never seen a Ruger transfer bar break, I have seen Taurus and Smith hammer block bars fail. Again, most of these occur when the gun is new.

Like anything new, it took awhile for shooters to trust these safeties and a lot of the older shooters still felt unsure about carrying six rounds in a revolver for a long time.