S&W Hammer Camming Forward Problem

[JTROKS]

MIM parts are hard, but there are parts that may not have fully hardened to the correct depth. Inspect the tip of that DA sear and see if it’s out of shape. Some MIM parts can be cleaned, but polishing is a different story. S&W will fix the revolver if the owner email or call customer service.

[ojisan]

I never said that short stroking would cause peening.
The OP even said that the surfaces are not damaged.
Short stroking is more likely to cause bending of pins and parts than peening.
Bending of pins or parts can result in the parts being out of alignment which is what we have here.
The OP asked how this problem could happen, I just offered a possible cause.

[dfletcher]

I can't speak to the cause other than the hinged area of the DA sear perhaps wearing in just enough for the DA sear to drop just a tad in its fit for the bottom of the DA sear to be too long and encounter the trigger.

Be careful stoning the bottom of the DA sear. Changing any angle will change the feel of the DA pull. My suggestion would be to start with some 600 or even 1500 grip Wet N' Dry metal sanding paper rather than the stone.

[unclerandy]

I can't speak to the cause other than the hinged area of the DA sear perhaps wearing in just enough for the DA sear to drop just a tad in its fit for the bottom of the DA sear to be too long and encounter the trigger.

Be careful stoning the bottom of the DA sear. Changing any angle will change the feel of the DA pull. My suggestion would be to start with some 600 or even 1500 grip Wet N' Dry metal sanding paper rather than the stone.

Master revolver smith Will O'Hara confirmed that the DA sear doesn't have enough clearance or "wink" as they call it. I confirmed this with a .010 thousandths feeler gage and it wouldn't clear. I put the DA sear in a mini precision machine vise keeping the angle of the sear nose and stoned it. I had to do this twice as the first time wasn't quite enough. I put it back together and couldn't get it to malfunction unless I intentionally tried to by short stroking it. I took it apart again and put in a Wilson spring kit and it feels awesome. I'll shoot it tomorrow and see how it goes. Video to follow. Thanks for all the input.

[ojisan]

It's good that you had to do it twice.
It's so much better to remove not quite enough and having to remove a little more than removing too much the first try.
Great to hear that you got it figured out.


I suggest testing it with the original springs first, it's always best to change one thing at a time when trouble shooting.
Once you know the problem is fixed, then you can try other things.

[JTROKS]

It's good that you had to do it twice.
It's so much better to remove not quite enough and having to remove a little more than removing too much the first try.
Great to hear that you got it figured out.


I suggest testing it with the original springs first, it's always best to change one thing at a time when trouble shooting.
Once you know the problem is fixed, then you can try other things.

[ysr_racer]

Master revolver smith Will O'Hara confirmed that the DA sear doesn't have enough clearance or "wink" as they call it. I confirmed this with a .010 thousandths feeler gage and it wouldn't clear. I put the DA sear in a mini precision machine vise keeping the angle of the sear nose and stoned it. I had to do this twice as the first time wasn't quite enough. I put it back together and couldn't get it to malfunction unless I intentionally tried to by short stroking it. I took it apart again and put in a Wilson spring kit and it feels awesome. I'll shoot it tomorrow and see how it goes. Video to follow. Thanks for all the input.

How did the clearance change? It used to work properly, then it changed, right? I wonder what changed to cause the clearance to shrink?

[Revoman]

I agree Brad. Although it's fixed....
I'm thinking that the issue as actually at the cylinder release sear, it's not allowing the full return of the trigger to clear. There is something causing that to happen, like some unburnt powder hindering maybe? A thousandth ain't much and that'd do it.

[unclerandy]

How did the clearance change? It used to work properly, then it changed, right? I wonder what changed to cause the clearance to shrink?

My theory is that because the front edge of the sear had a sharp edge it "wore" a little bit of a shelf that became an issue. Also its possible that as things "settled in" something could be slightly out of spec but not broken.

[unclerandy]

I agree Brad. Although it's fixed....
I'm thinking that the issue as actually at the cylinder release sear, it's not allowing the full return of the trigger to clear. There is something causing that to happen, like some unburnt powder hindering maybe? A thousandth ain't much and that'd do it.

Thanks for the input. I can confirm that the trigger always returns fully forward metal to metal contact of the trigger and frame. In any case its fixed and working great.

[ysr_racer]

So....


....operator error?

[unclerandy]

So....


....operator error?

No. I stoned the DA sear until it had the proper clearance.

[Revoman]

All in all, you did a good job in tracking this issue to ground.
Congrats on your 'Columboism'!
mike

[unclerandy]

All in all, you did a good job in tracking this issue to ground.
Congrats on your 'Columboism'!
mike

Thanks to everyone here who contributed. I learned a lot.