642 Making a "Different" Sound

[DAdams]

Clacking Instead of Clicking

I have a new 642 and have had it to the range once and put about 50 rounds through it flawlessly.

I have been dry firing it to smooth out the trigger.

Instead of the normal sound one would hear when dry firing, mine now makes a "hollow clacking" sound instead of the normal metallic ring and when in this mode the trigger become lighter and shorter. Then it will "reset" for awhile. It is becoming more frequent as time goes on.

The pin looks like it is coming out to the same extent, but perhaps not with the same force?

When I smack it on the right side with my palm I can make some sort of adjustment internally.

Guess it needs to go back to the mother ship. Anyone else heard of and or experienced this?


I sent an email to S&W Customer service with a description. And to think I got a "reliable' revolver to carry me over while I was breaking in the
auto PM 9.

 

[jad0110]

As others suggested in your 642 Club post, check your strain screw first to make sure it isn't "backing out".

 

[DAdams]

Strain screw would be where?

 

[Brian Williams]

tain't a strain screw on a J frame.

 

[DAdams]

Clacking Sound Update

Update:
Wednesday, March 22, 2007
10:10am EST

I posted this on the S&W Forum yesterday after posting it here.

I just finished an analysis based on arfmels comment in the posted Gunsmithing Thread. I also just updated the S&W Forum Revolver Thread.

http://smith-wessonforum.com/eve/forums/a/tpc/f/530103904/m/1861058112

http://smith-wessonforum.com/eve/forums/a/tpc/f/580103904/m/2881068112

You may wish to monitor these for going forward results as I don't know that I am going to update 4 sites, since I have a day job.


Originally posted by arfmel:
Please God don't let it be a lock malfunction...


You bring up an interesting point, and one that never crossed my mind, until now.
My initial response is if I send it to S&W for repair and it is the lock will anyone ever be told?
So..this morning I dig out the box, find the keys, read the instructions (novel eh?) and here are the results. (This analysis and operational data was done real time while writing this). Cylinder open, gun unloaded, turn key approximately 90 degrees ccw until it stops.

I am assuming at this point one would store the gun away with the lock on and the cylinder open, but nowhere is that stated.
In this state I can:
I) Load the cylinder
II) Close the cylinder (loaded or unloaded)
III)Unloaded cylinder open, lock engaged.
Pull the trigger and it will detent with half the pulls, not detent on about half). There is no firing pin appearance. How should the trigger respond with the lock engaged? Trigger detent or not?

Here is the most interesting experiment!
Lock engaged with the cylinder open. Close the cylinder, pull trigger.....the aforementioned clacking sound and the cylinder rotates, and with no firing pin appearance.

I then opened the cylinder, unlocked (90 degrees approx, cw). Closed cylinder, pulled trigger, clacking sound, cylinder rotates, firing pin appears, but I don't think that since the spring is fully charged it has enough hammer to discharge a round. Pull trigger 10 times, 4 clack, 2 normal, 4 clack.

Dry fire 50 times 4 clacks 5 normal 41 clacks.

Since engaging and disengaging the lock for this experiment I can tell you that this thing is now a majority "clacker" and probably would not fire.

I think it is safe to say that it is a lock issue. Being a student of science and mechanically savy I would say that the lock design failure mode is to failsafe, ie never fire.

Having said that I am glad that I did not have to count on this particular 642 for protection.

Since I am not a gunsmith and have no means of doing a failure analysis myself, I suspect that when I am eventually contacted by Customer Service I will be given an RGA, send it in, get it back and I wonder what the "trouble found analysis" will be or would have been?

Guess I will go do a search on lock failures and see what I come up with.

 

[alank2]

>Being a student of science and mechanically savy I would say
>that the lock design failure mode is to failsafe, ie never fire.

The lock is very poorly designed. I agree that you have a lock issue. I don't think the trigger or hammer should move when it is locked, so you should have never been able to make it rotate the cylinder.

Issues with the lock:

The first issue: Is that it exists at all.

The second issue: The so called key does not have any teeth on it and is no more than a "screwdriver" to turn the so called "lock". The lock does not have any mechanism to lock it into place, unlocked or locked. It is free to rotate to either position locked or unlocked and it is probably possible that recoil can rotate it. That is the first issue.

The third issue: When in locked mode it forces the flag to lock the hammer, but when in unlocked mode it does NOT force the flag to free the hammer. Instead of relies on a very small, weak, and flimsy spring to push the flag out of the way. I was shocked at how terrible this was, when I had my 442 apart I turned it upside down and the weight of the flag made it move part way into the hammer locking channel.

These locks are horribly designed. I don't like the idea of the lock at all, but if they must foist them on people at least design the darn thing so that it is reliable.

Good Luck,

Alan

 

[langenc]

Alank2 please send to S&W.

 

[alank2]

Hi,

Do you mean the original poster send to S&W ?

Thanks,

Alan

 

[loplop]

tain't a strain screw on a J frame.

Thanks for correcting me on that, I see Brownell's schematic is incorrect in that regard!

 

[jad0110]

tain't a strain screw on a J frame.

Very true, brain fart on me!

 

[orionengnr]

please keep us updated.
Good luck.