Lumpy DA trigger pull

Geezer7

Geezer7

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I have a 38/44 Outdoorsman with a DA trigger that "stacks" in the middle of the pull, then lightens again at the end.

I installed a new hand--with no improvement.

It feels like 2 moving parts are mating poorly. I noticed that the thickness of the hammer is less than the trigger, but they seem to engage OK.

Any suggestions?

Thanks in advance
Bruce
 
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What about a wobble? Will either piece wobble side to side. Trying to imagine that feeling in my head that’s all I can come up with. So you replaced the hand maybe just remove the hammer, make sure everything is clean and lubed then reinstall.
 
Sounds like the timing of the hand-off of the hammer over to the DA cam on the trigger. If the sear is too short, the hammer enters the interface a bit too low, and rubs (bumps into) on the trigger's DA cam. The hammer has to enter the "window" below the trigger bevel unrestricted.

Check the condition of the sear, it may be a bit too short.....






Carter
 
Last edited:
I've ordered a new (used) one from Jack First. Will advise results.

Thanks SO much!
 
Bummer--the "new" one was the wrong part.

However, I've noticed 2 things perhaps significant:

1) With the cylinder removed, the DA trigger pull is silky smooth--no binding of the action despite the sear being a bit short. Hmm...

2) With the cylinder in place, the DA pull is reasonably smooth when dry firing...

3) ...until the gun is live-fired a dozen or more times in close succession. Could metal expansion from the heat be causing binding somewhere in the action? And could that somewhere be where the heat is being generated--the cylinder and tip of the hand where it touches the extractor star gears?

Please excuse my amateur diagnosis. I await your expert advice.
 
Geezer7 said:
Bummer--the "new" one was the wrong part.

However, I've noticed 2 things perhaps significant:

1) With the cylinder removed, the DA trigger pull is silky smooth--no binding of the action despite the sear being a bit short. Hmm...

2) With the cylinder in place, the DA pull is reasonably smooth when dry firing...

3) ...until the gun is live-fired a dozen or more times in close succession. Could metal expansion from the heat be causing binding somewhere in the action? And could that somewhere be where the heat is being generated--the cylinder and tip of the hand where it touches the extractor star gears?

Please excuse my amateur diagnosis. I await your expert advice.
Click to expand...


Could be heat expansion, could also be fouling build up on the edge of the forcing cone and possibly cylinder face. If the binding disappears after allowing the revolver to cool and without cleaning, then it is a heat expansion issue.

I'd check the cylinder end shake and the barrel-cylinder gap. Too little barrel-cylinder gap will cause binding when there is fouling present and if the revolver gets hot and the steel expands a little, then a nearly non-existent gap becomes a binding point.
 
stansdds said:
Could be heat expansion, could also be fouling build up on the edge of the forcing cone and possibly cylinder face. If the binding disappears after allowing the revolver to cool and without cleaning, then it is a heat expansion issue.

I'd check the cylinder end shake and the barrel-cylinder gap. Too little barrel-cylinder gap will cause binding when there is fouling present and if the revolver gets hot and the steel expands a little, then a nearly non-existent gap becomes a binding point.
Click to expand...

I’d say this diagnosis hits nail on the head.
 
Dear standds

Bingo!!!

I just checked the bbl-cyl gap and it is VERY tight, and when I opened the cyl and looked at the end of the forcing cone, it has very shiny metal showing on the top edge, and a less shiny area on the left side.

And--I had previously noticed that even when cold, one in six DA pulls was just a little bit lumpy. Now when I watch the bbl-cyl gap when I pull the trigger DA, guess what?--when the slightly tight pull starts, the bbl-cyl gap closes entirely.

I can push the cylinder back almost 1mm and then hold it there while pulling the trigger DA and see normal bbl-cyl gap while doing so.

So how do I fix? I am good with internals, but ignorant of all else.

Do I just need a new gas ring? or extractor rod collar? Can I just shave a bit off the end of the forcing cone (I can hear you groaning)?

Again--MANY THANKS!!
 
Hold the phone...I see what might be the issue.

The extractor rod knurled end that clicks into the barrel shroud has been ground down and has about the same amount of fore-aft movement as the cylinder.

Do I just need a new extractor rod??
 
First, have you removed the extractor rod and cleaned the end and the hole in the extractor? Second, on the back side of the extractor there are two holes for the location pins. Dirt can accumulate in those and stop the extractor from fully seating. I use some dental pics to clean them out, use what you've got. I was amazed the first time I did this, you just don't think enough dirt would get in there but it does. Hope that works, it's an easy fix if that's the problem.
 
Thanks for the tips.

1) The extractor rod end is clean.

2) The extractor star locator pins and holes are clean. The star lays flush/slightly below the plane of the cylinder face.

Cylinder end-forcing cone gap is still too tight...
 
Geezer7 said:
Dear standds

Bingo!!!

I just checked the bbl-cyl gap and it is VERY tight, and when I opened the cyl and looked at the end of the forcing cone, it has very shiny metal showing on the top edge, and a less shiny area on the left side.

And--I had previously noticed that even when cold, one in six DA pulls was just a little bit lumpy. Now when I watch the bbl-cyl gap when I pull the trigger DA, guess what?--when the slightly tight pull starts, the bbl-cyl gap closes entirely.

I can push the cylinder back almost 1mm and then hold it there while pulling the trigger DA and see normal bbl-cyl gap while doing so.

So how do I fix? I am good with internals, but ignorant of all else.

Do I just need a new gas ring? or extractor rod collar? Can I just shave a bit off the end of the forcing cone (I can hear you groaning)?

Again--MANY THANKS!!
Click to expand...


You know what they say about a blind squirrel? Once in a while, even it finds an acorn. Ok, you have somewhere close to 0.004 inches of cylinder end shake and insufficient barrel-cylinder gap. A good fix would be to obtain some cylinder shims (bearings) to push the cylinder backward on the yoke. This will reduce the end shake and create barrel-cylinder clearance. Do not completely eliminate the end shake, you do need 0.001" for smooth cylinder rotation.



The following link will take you to a manufacturer of these shims.
S&W K L N Revolver Shim Kits
 
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