S&W Revolver Safety Features

[westernrover]

It seems to me that the transfer bar is simpler and better way to do this task. Why doesn't S&W use a transfer bar?

A transfer bar is repeatedly hit every time the revolver is fired or dry fired. Predictably, it breaks at some number of impacts. I have a Ruger with a transfer bar and I don't expect it to break in my lifetime. Other people fire theirs much more often and would need to consider replacing it at some interval. I don't care to speculate what that interval might be, but there are certainly records of broken transfer bars.

S&W can rightfully consider their design that only blocks the hammer when the trigger is not pulled to be a better design. I have a S&W too and this being my double-action revolver (the Ruger is SA), I would certainly expect to exceed the life of a transfer bar if it were to have one. I've fired it tens of thousands of times and could expect to continue to accumulate round-count for decades to come. It could have a transfer bar which I would replace to prevent failure, or it could simply not. Since a broken transfer bar results in a failure to fire and there is no practical expedient way to resolve the malfunction in use, I prefer the simpler design that has no transfer bar and does not depend on any additional part to function, least of all one which gets repeatedly hammered.

 

[Durango_Dave]

The hammer block is almost the opposite of a transfer bar.

The hammer block must be out of the way or it prevents the primer from being hit.
The transfer bar must be in in the way or the primer will not be impacted.

Despite this Charter Arms says:

Charter invented the hammer block transfer bar safety system used by almost every revolver manufacturer.

as if the hammer block and transfer bar are one thing.

https://charterfirearms.com/pages/about-us

It makes me wonder if Charter Arms had two separate patents for the two safety mechanisms or one patent that encompassed both.

Of course now the patent has expired and anyone can copy these ideas.

 

[Jim Watson]

• Completely blocked hammer system cannot fire unless trigger is held in full rear position - safest revolver design in the world. In fact, Charter invented the hammer block transfer bar safety system used by almost every revolver manufacturer.

This would be news to those revolver manufacturers in business for over a hundred years.

 

[westernrover]

As if Douglas McClennahan, founder of Charter Arms, didn't learn everything he knew about revolvers from Colt, High Standard, and Sturm Ruger all of whom he worked for prior to founding Charter as late as 1964. It is true that Charter's "Undercover" model introduced the transfer bar in the 1960's, whereas Ruger didn't adopt it until, nominally, 1973 (they must have began the process at least a little earlier).

The .38 S&W Military & Police Model of 1905 4th Change, introduced 1915, incorporated a passive hammer block. The design was modified in 1945 to include an improved hammer block after a sailor was killed by a loaded revolver discharging when accidentally dropped onto a steel deck. The change was introduced about 1947. The spring-loaded hammer block safety was either replaced or augmented with a cam-actuated hammer block that rode in a channel in the side plate, possibly in 1968. In any event, Charter has never used a hammer block, but their revolvers feature transfer bars -- the very opposite of a hammer block as pointed out two posts above.

 

[Jim Watson]

It is true that Charter's "Undercover" model introduced the transfer bar in the 1960's,

I saw a Iver Johnson “Hammer the Hammer” ad a lot earlier.

 

[westernrover]

That's rich. It looks like that goes back to 1893 and might have been the work of none other than Oscar F. Mossberg at Iver Johnson. I tried to pin down the patent and the date, but I'm getting bad data. An 1893 patent is referenced but it appears to pertain to the latch on the top strap. Another source says "around 1908."

I also enjoy to be reminded that guns and bicycles are related, and naturally motorcycles followed.