Hammer firing pin vs. transfer bar

[leadcounsel]

I'm looking at buying a revolver with a hammer firing pin. It's a S&W 64-3 made in the 1980s.

All my revolver experiences have been with revolvers that have the more modern transfer bars.

So what are the practical differences? Are the hammer firing pins less safe? Drop safe? Carry on loaded chamber safe?

And how is the model 64-3 (.38spl)?

 

[MCgunner]

I prefer the transfer bar, less fragile. But, use snap caps when you dry fire and should have no problems. I wouldn't pass on a 64 just because of that. It's a good gun and I like stainless. I have a 60s M10 that is the blued equivalent. Very accurate, very well made revolver. Only trouble I ever had with it was a cracked forcing cone. If you shoot lead bullets, make sure to keep an eye out for lead build up back near the forcing cone. About all I ever shoot in it is lead. I think that's what caused that particular problem, but not sure. I put a 4" heavy barrel on it and it is still going strong.

 

[Jim K]

I disagree on the "fragility" of a transfer bar vs a hammer block safety. In my limited experience, I have seen transfer bars (mainly on older guns) break; I have never seen the Colt positive safety or the current S&W hammer block break. (I have seen the older - pre-1944 - S&W hammer block safeties break.)

I don't think anyone could call the transfer bar "modern"; AFAIK, its first use in revolvers was by Iver Johnson, in 1893.

Note that the transfer bar requires a frame mounted firing pin, but the hammer block will work fine with either the hammer mounted or the frame mounted firing pin. S&W's change to frame mounted pins had no effect on the way their hammer block works.

Jim

 

[leadcounsel]

Sorry my terminology may be incorrect. Maybe I'm thinking of the hammer block bar on my Ruger GP100.

The question remains, is the firing pin location ON the hammer a universally outdated design and any more unsafe? Undesireable? Any reason why it would be undesireable?

 

[branshew]

It's not any more unsafe IMO although the transfer bar adds an extra layer of safety assuming that the design puts it out of alignment with the frame mounted firing pin until the trigger is pulled. The hammer block will prevent the firing pin on the hammer from ever making contact with the primer or will prevent the hammer from contacting the transfer bar. I have an older model 10-5 and I haven't had any issues. I actually like the older design. It looks more authentic.

 

[leadcounsel]

http://firearmsid.com/A_FirearmFunction.htm

Answered my own question with some Google-foo...

 

[scarredpelt]

Haven't there been a few cases of transfer bar style firing pins being inertia fired?

 

[9mmepiphany]

Haven't there been a few cases of transfer bar style firing pins being inertia fired?

i haven't heard of any...it would have to overcome the firing pin spring first

 

[scarredpelt]

i haven't heard of any...it would have to overcome the firing pin spring first

It's just that I could have sworn that there were but I've been searching here and google without success, so it is more than likely a tale from beyond.

 

[Steve C]

So what are the practical differences?

There is no practical difference with double action revolvers. Both work well and they are equally safe and equally reliable. I have both types of firing pin systems in the various revolvers I own and have absolutely no preference.

 

[1911Tuner]

I prefer the aesthetics of the hammer mounted firing pin...aka "Hammer Nose." It just looks right, somehow. It's probably due to me having cut my teeth on my grandpa's
old .44-40 Frontier Colt...but there really is no practical difference between the two, either in safety or reliability.

Ruger's system isn't a hammer block, but rather a transfer bar that moves up and acts as a connector between the hammer and the frame-mounted pin...and down as a disconnect when the gun isn't being readied to fire as the trigger is pulled.

As with any spring-loaded, inertial firing pin that doesn't have a blocking mechanism, dropping the gun can result in a discharge...but it has to be dropped pretty hard straight down onto the muzzle onto a hard surface for that to occur. Due to the pin's low mass, the revolver would probably have to be dropped from a height of 25 feet, assuming a good spring. (Please hold the fire-breathing comments on the height. It was a WAG with no basis in experimentation.)

 

[WardenWolf]

The main difference is that you're much less likely to incur damage or breakage to a transfer bar than to a hammer firing pin. The transfer bar system leaves the striking point protected within the gun's innards, and ensures it strikes the primer in a straight line rather than with angular motion. The extra angular rotation a hammer firing pin has results in higher stresses of impact than a simple hammer striking a flat surface. The hammer design in a transfer bar revolver can be more compact and blunt, resulting in a more direct strike (more power imparted) and less stress applied to the hammer.

Effectively: with a transfer bar system you are less likely to suffer a firing pin break and, in the event of a break, it is generally simpler to repair.

 

[1911Tuner]

The main difference is that you're much less likely to incur damage or breakage to a transfer bar than to a hammer firing pin.

Well...I dunno if I'd go quite that far. It may be true in theory, but...assuming that nothing is dimensionally wrong with the gun in question...the hammer mounted pin is on a par with the other two systems. In all my years with Smith & Wesson revolvers, I've never had one of mine break, and I've only known of two that did. I've seen three Ruger transfer bars break, and twice as many frame-mounted firing pins that chipped or broke.

Single-actions with hammer noses were prone to breakage on the old versions, but not so much these days, except in the cheap clones...and even those aren't consistently bad. It's mainly a matter of proper heat-treating.

So...A little less likely maybe. Enough to say that one is vastly superior? Nah.

 

[StrawHat]

When I was shooting in competition, all my revolvers had hammer mounted pins. Never had one fail, chip, break of fall off. The only frame mounted firing pins I dealt with were on my 22 revovlers.

All my competition revolvers were S&W.

 

[Gato Montés]

So......can hammer mounted pins be safely dry fired?

I know this has been rehashed over and over again, but each subsequent search brings me a different answer, some yes, some no.

 

[StrawHat]

Nasser So......can hammer mounted pins be safely dry fired?

With a S&W revolver, yes.

 

[rcmodel]

Effectively: with a transfer bar system you are less likely to suffer a firing pin break and, in the event of a break, it is generally simpler to repair.

I haven't found that to be the case at all.

I have seen firsthand, and heard more reports of broken transfer bars then all the hammer mounted firing pin problems combined.

The S&W system was a tried & true system that lasted for almost 100 years. Had there been a problem they would have fixed it 75 years or more ago.

IMO: The principal reason for the switch to the new frame mounted firing pin by S&W had way more to do with "cheaper to make" MIM hammers then any reliability problems with the old design.

rc