Binding/timing issue.

[Verndari]

I have a 627 in which I have been working on. I currently have the trigger weight at ~5 lbs. As I go over my work, I notice that  4 chambers are harder to pull than the others on the other side of the cylinder. 3 of these 4 are slightly out of time (1, skip, 3 then 4). I didn't have this issue with the heavy factory weight, and no, I did not touch the inside or too if the hand, nor the ratchets. This is more pronounced when I ease the trigger. When I hammer through the trigger, it seems to lock in all 8. Everything functions fine with the cylinder out.

 

Even though I can't visually see it, I am thinking the ejector rod is bent or something is wrong with the yolk and binding the cylinder, causing the issue. Am I thinking correctly? 

Edited May 24, 2018 by Verndari

[357454]

If your extractor rod is bent enough to cause the problems you are experiencing you should be able to see the end of the extractor rod wobble when spinning the cylinder with it open.  This can be cured by straightening the extractor rod.

  Generally if you have higher trigger pull on a few cylinders it is because the ratchet needs to be adjusted for proper fit to the hand by thinning it, this condition normally has correct timing. If you have cylinders that do not lock up, this is because the hand is too thin and will need to be replaced and proprerly fit.

[Verndari]

I removed parts in play and put the cylinder back in. I spun it and found it will not spin freely. The chambers in question are binding more so. Opening the cylinder when the chambers in question are at the top or to the right is very difficult. put them down or to the left and the cylinder opens. I am starting to see wear marks on the frame where the ratchets meet (this is a 627-5 but for all intents and purposes a new gun). Applying a black marker on the ratchets  shows some high spots. 

[357454]

The ratchets should not be contacting the frame, there is a boss on the end that acts as a bearing surface, do you have a tool to verify the crane alignment? If not a local gunsmith should have one and can check the alignment if a few minutes.

[Verndari]

I don't, but Brownell's will... I created a reference point along the extractor rod and I do see wobble. Don't know by how much as I don't have a tool to measure it... Yet....

[ima45dv8]

With the muzzle straight up and the cylinder open push and hold down on the extractor rod. With something like a camel hair brush clean the exposed rod. Try to force the brush up a little where it enters the cylinder. 

 

I had a few grains of burnt/un-burnt powder causing very similar symptoms and even though I couldn't see them very well, this knocked them loose and the binding on the cylinder and extractor rod went away.

 

HTH...

[Verndari]

My tools came in. Crane is fine. The extractor rod has .004" run out. I found the spring in the thumb piece was short and replaced it. That fixed the binding issue. The timing is ever so slightly off on the same chambers. I am currently fitting a new hand to fix the timing.

 

I bought this gun as used. The timing was fine in single action. Didn't notice the issue before with the 1 ton double action trigger pull. I had polished the rebound slide, changed out the rebound spring and installed an APEX hammer. That was when I noticed problems.

 

Thanks. 

Edited May 30, 2018 by Verndari

[Toolguy]

The lighter the trigger pull, the more things you can feel that would go unnoticed in a heavier action.