S&W model 638-3 firing pin

[Delos]

My S&W 638-3 firing pin is okay (after much study of what the engineers are doing)

Perhaps my main point here is to get not only the words floating firing pin, but also the (older?) words "inertia firing pin", in same post for any other old folks who might get as confused as I did, and are searching the internet.
I have had many jobs where pistols were involved at some level, where you had no time to test fire the pistol just issued. I first learned to check a pistol by watching others, and in classes. The classes were rather basic and mostly safety oriented.
Watching retired soldiers, or ex-police was another story. They looked at everything before accepting an issue weapon. Somewhere I saw at least one checking not only the firing pin hole (looking and feeling), but also how far the firing pin sticks out when hammer lowered down on it.

Short story is my beautiful new 638-3 failed the test I have done for years working prisons, occasionally gun towers, court escort, or transferring inmates to other prisons. No way would I have accepted an issue of this pistol - back in the day when you could look at a revolver and know it will work.

But having read numerous Jeff Cooper articles and such, somewhere I had long ago became familiar with the concept of the 1911 45 auto's inertia firing pin. One of the lesser known safety devices making it safe to accidentally drop on a completely un-cocked hammer. Because the firing pin is already pushed in even with the frame it can go no further from energy transfer.

Anyway with my nearest shooting range miles away and covered by snow I spent hours searching the internet. After finding the word "floating firing pin" in one gun review I knew I was getting closer. Finally a review that used the word "inertia firing pin" Finally a link took me back at this site with only one post mentioning light primer strikes. (Obviously this must not be an issue if the subject is so hard to find).

I read my manual again - mostly usual safety and lawyer warnings. Searched for any reference to Inertia firing pin. Finally found one. I went to the Smith&Wesson web site. Clicking on the "Resources" tab takes one to a page with many books and such listed. On the left border the vertical list has "Owners Manuals" (those things you would expect to be in the box when you bought the pistol).
On the next page, center of page, go down and click on "Revolvers - Modern Style". (Nope not here).
Okay now click on "Parts List" - no schematic - now go back and search the internet.

Somewhere, two days ago, I found a schematic showing all the parts of the 638-3 (or maybe just 638). So far not lucky today.

After seeing the firing pin in picture form I took a round toothpick and pushed it further in from hammer side. Finally the right amount of firing pin gets exposed past the firing pin hole. Confirming my hunch that it is an enertia firing pin.

Yes now fairly confident with new purchase I will find a dry day for the range, or find some reloader to purchase some empty but primed 38 special shells, to see if they fire. I am sure all will be fine, and I can shoot it next summer for sure. My older model 60 still works fine and is only 5 or 6 ounces heavier perhaps. I wanted to get out of the habit of putting my thumb up by the hammer when taking M-60 from pocket. Not a good habit when one also shoots semi-autos.
They over-engineered something that was perfect. And reduced the hammer to thumb surface by about half. Guess I need to buy an older one with low mileage and give this one more thought.

 

[Delos]

Continuing the learning curve and comfort level.

After reading several articles about Metal Injection Molding I am comfortable with that new technology that makes perfectly shaped parts. That and the computer machining of other parts that leaves me with a very tight revolver.

I am comfortable with frame firing pins traveling straight being easier on the frame than the arc swing of the hammer mounted (splitting hairs For most of us?) I am comfortable with the fact that the frame mounted firing pin can be changed without mailing it in, as a hammer mounted is for most of us. Also never know whey you want to remove a part to disable a gun that is inside a safe for long term storage.

I am a bit ho-hum about the lock. It is there - if I remove it more dust can get inside. If given a choice in a gun store I would buy one without it.

When my 638-3 is empty, and I cock the hammer and point it at ceiling, drop a pencil down the barrel eraser first, and snap the hammer, my model 60-7 bumps up the pencil about twice as far. But the model 60-7 has a firing pin that protrudes though the hole further, perhaps responding to more head space (looser cylinder than the new technology). I assume the 60-7 hammer is a heavier hammer?

I am sure everything will be fine when I finally fire it and examine the dent in the primer.

One parts diagram of this 638 or a similar model showed the firing pin having a gap in front of it (naturally it is bigger at back end and must move forward, but the picture also showed it much fatter inside as I would expect an inertia firing pin to be in order to transfer enough energy. Perhaps if it got over-oiled or dropped in a stream it would be prudent to dry fire it a few times to get any oil or water out from that area. Unless it was a hot day and a cold stream it is doubtful any water would get inside that area in a few seconds. (A friend of mine got a surprise when he was wearing an early water proof watch on a hot day and put his hand & wrist in bucket of cold water. The cooling of the watch sucked the water right in.)

So far my new handgun gets an A++.

 

[ogilvyspecial]

Delos, I don't know if you've seen this thread or not.

http://smith-wessonforum.com/s-w-smithing/233879-s-w-j-frame-firing-pins-frame-mounted.html

I'm still finding that the pins in the current J Frames (#22952) are still running
slightly shorter than the pins I bought directly from S&W earlier this
year. Why that may be I know not, luck of the draw perhaps?

I'm getting low on the 22952's so ordered another batch, directly from
S&W, a few weeks ago. For what it's worth, they are out of stock
and have been on backorder since my order was placed.

 

[Delos]

Thanks Ogy - I will read that several times.
When I had a 1911 colt 45 auto years ago I first became familiar with an Inertia firing pin as one of many safety devices. When I first heard that it cannot touch the hammer and primer at the same time I immediately locked the slide back and checked. Yes when the firing pin is pushed to the frame (actually the retainer), then the other end of firing pin is not sticking out.

Naturally I tried over and over. It is at first hard to believe the hammer can hit the firing pin -- then the firing pin can travel the extra distance on its own striking the primer with just its own weight.

When you bottom out the hammer end of the firing pin on my new 638-3 the point just barely sticks out the firing pin hole at the other end. When you push it in further actually into its hole beyond the reach of the hammer, it comes out almost as far as my similar but older J-frame revolver, that has hammer mounted pin.

In other words it is the old "inertia" firing pin. No doubt the extra mass of the pin is very necessary.

I have read that you can buy longer pins that will reach the primer in the regular way. Sounds like any longer pin would be longer on the hammer end of the pin. The primer end of the pin already bottoms out at the right length. The rebounding hammer would certainly move back far enough to clear a longer end sticking out toward it. But the hammer block thickness is another question?

I fired my 638-3 today and it works fine. I will not be changing anything.

I have other guns so I move slow and deliberate. My two and a half year old Glock Gen 4 is finally ready for me to take to the range. The shell rim did not feed up under the extractor as easy as I wanted (long story). Finally I got enough oil around the extractor and its spring, and moved it enough, that it is moving as expected when pushed by Ice cream sticks. Feeds nice when lowering slide slowly. Some people I respect told me they are not supposed to feed slowly just take it out and shoot it. I did not like the way the bullet heads hit the ramp hard, so spend a weekend here and there with the learning curve.

My first generation glock 17, in 9mm, has me spoiled and I wanted more from my Gen 4 in 40 cal, than I felt and saw. Eventually my next purchase will be a Sigma or PD9 (more on all that later).

 

[Delos]

Delos, I don't know if you've seen this thread or not.

http://smith-wessonforum.com/s-w-smithing/233879-s-w-j-frame-firing-pins-frame-mounted.html

I'm still finding that the pins in the current J Frames (#22952) are still running
slightly shorter than the pins I bought directly from S&W earlier this
year. Why that may be I know not, luck of the draw perhaps?

I'm getting low on the 22952's so ordered another batch, directly from
S&W, a few weeks ago. For what it's worth, they are out of stock
and have been on backorder since my order was placed.

Hello Ogy
Let me make a wild guess about the newer shorter firing pins.

My understanding of the old 1911 inertia firing pin was that it was protection against dropping pistol on the hammer and it firing. It needed the inertia of the hammer to go forward of the firing pin hole.

When I hold my 638-3 sideways up to my overhead light (empty) and lower the hammer a small amount of the firing pin is seen sticking out the hole. Not enough to fire the gun I assume.

My understanding of the old inertia firing pins was that they could never touch the primer and hammer at the same time.

S&W revolvers have so many safety features this is a ridiculous subject to me.

But just for curiosity -- if you have one with the shorter firing pin installed please hold it (empty) up to the light sideways and lower the hammer. With the hammer down can you see any of the firing pin. (I am betting you cannot).