SIGforum
Seeking possible diagnoses of J-frame problem

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October 02, 2017, 07:18 PM
wrightd
Seeking possible diagnoses of J-frame problem
After I partially disassembled, cleaned, and lubricated my j-frame 641-1, I filled it with snap caps and did a function test. When I pull the trigger slowly, it operates normally. But when I pull the trigger fast, such as a fast double or triple tap, it fails to advance the cylinder about every other trigger pull or so. The cylinder advance thingy looks good a sharp with no damage. I can't figure it out.

Any ideas of things to check ?




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Wile E. Coyote School of DIY Disaster
October 02, 2017, 07:25 PM
cas
I've seen this before but my brain is fuzzy of dust and fuzzy memories.

ETA: Re-read.

Did you remove the hand from the trigger? If so and you didn't put it back on the proper side of the spring (in the trigger), that would do it.


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October 02, 2017, 07:31 PM
4MUL8R
Www.smith-wessonforum.com has very knowledgeable people.


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October 02, 2017, 08:06 PM
LtJL
what CAS said.
October 02, 2017, 08:06 PM
henryarnaud
Are you releasing the trigger all the way between shots? Sometimes rapid-firing a DA revolver results in short-stroking, especially for people who do most of their shooting with SA, DA/SA, or striker-fired guns.



"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." Sherlock Holmes
October 02, 2017, 09:08 PM
wrightd
I didn't know that was possible, short stroking a DA only revolver. I'll try again to make sure I'm not doing that.




Lover of the US Constitution
Wile E. Coyote School of DIY Disaster
October 02, 2017, 10:06 PM
henryarnaud
Yup. If you don't let the trigger forward until it resets, the next trigger pull won't advance the cylinder. It usually happens when trying to fire quickly. The fact that you were able to "fire" it when shooting slowly but failing when doing double and triple taps makes me think this is the likely cause.



"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." Sherlock Holmes
October 03, 2017, 12:14 AM
YooperSigs
Agree.... It is possible to short stoke a DA revolver.


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October 03, 2017, 12:43 AM
sns3guppy
quote:
Originally posted by wrightd:
I didn't know that was possible, short stroking a DA only revolver. I'll try again to make sure I'm not doing that.


Absolutely possible, and likely if you don't ride it forward.
October 03, 2017, 04:29 AM
Mars_Attacks
I agree the hand spring is off.

Short stroking a revolver advances the cylinder without dropping the hammer.


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October 03, 2017, 07:30 AM
henryarnaud
Just tried it to be sure. It depends on how much the trigger is allowed to move forward before short-stroking. I can cause the firing pin to protrude without the cylinder advancing, or I can advance the cylinder without the firing pin protruding. I used two different guns, a 642-1 with a stock action and a 642 no-dash with a trigger job. It was easier to manipulate on the no-dash.



"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." Sherlock Holmes
October 03, 2017, 08:21 PM
wrightd
quote:
Originally posted by Mars_Attacks:
I agree the hand spring is off.

Short stroking a revolver advances the cylinder without dropping the hammer.

Hand spring. Will look that up. It wouldn't surprise me if I screwed something up. I already replaced the sear spring which I destroyed before learning how to get it back in without bending it. So this Hand spring, is this "easy" to replace ? My guess is not if it's part of the slide thingy assembly.




Lover of the US Constitution
Wile E. Coyote School of DIY Disaster
October 08, 2017, 10:47 PM
VictorLouis
The hand-spring holds the hand forward under tension. That is so it remains poking through the slot in the breechface in order to engage the teeth on the ejector star, and rotate the cylinder. If you went so far as to remove the hand and trigger as a unit, you would have noted that you had to pull back on the hand in order to clear it OUT of that slot, to be able to lift the assembly up and off of the trigger pin. Installing it, (assembly) would have been the same. You start the parts down onto the trigger pin, then pull the hand back to clear the side of the recoil shield and push the parts down against the inner left wall of the frame. Then, you would have had to probably finesse it up or down a wee bit to allow the hand to 'spring' forward back into it's slot.

You are most definitely short-stroking it. The hand is either under forward tension to do its job, or it's not. There's no 'tweener' spot for that part of the mechanism.
October 09, 2017, 04:30 AM
Mars_Attacks
If you were here in Georgia, I'd teach you to take these things apart and put them back together blindfolded.


____________________________

Eeewwww, don't touch it!
Here, poke at it with this stick.