Timing revolver after refinish

[mioduz]

I am not very proficient with revolvers, and in a bit of a bind looking for advice. I cerakoted a SW N frame and the timming apears to be off now. If I pull the trigger (in DA) quickly and with more force it will spin the cylinder and appears to work fine. But there is a "bump" in the trigger pull. If going slowly the cylinder binds up and it appears to be because the Cylinder Stop has not dropped down enough.

Any advice?

 

[BCRider]

Clearly enough you didn't mask off some of the more critical areas and now you've got some binding due to the thickness of the finish or where the finish wicked in where it wasn't supposed to go.

There's no magic bullet here. You or someone that fully appreciates how each part works will need to go through the whole action train and cylinder fit and remove traces of the Cerakote where it should not be to restore the operation.

Right off the bat I'd suggest that any of the Cerakote that is on the rubbing areas of the cylinder and frame or in the indexing pawls on the back of the cylinder needs to come off. You want the cylinder to sit back on the face of the recoil shield metal exactly as it used to be before the finishing. And going past that one basic area the openings for the hand and stop bolt should be checked to ensure no binding.

If you also re-finished inside the frame under the side plate then you may as well take the gun in right now to have the action done. Nothing good will come out of anything added in there.

 

[Old Fuff]

It may be that when the revolver was reassembled the cylinder stop spring was not correctly installed. The result can be that the cylinder stop binds and doesn't drop far enough. Also be sure that you don't have a blob of Cerakote in the wrong place.

 

[DPris]

How did you do it?
Strip frame completely?
Coat any internal small parts?
Denis

 

[mioduz]

How did you do it?
Strip frame completely?
Coat any internal small parts?
Denis

Yes I did strip down the entire gun and sprayed the entire gun frame inside and out. The trigger and hammer where both sprayed because the finish was both very poor on those parts. Both fit on the pins without issue. I have coated several 1911's and understand how pins can grow and holes shrink with the coating. All of the parts are fitting in to the frame nicely with no interference. Clearly something has changed though or possibly I just don't have something assembled 100%. again revolvers are not my forte and this was done more as a favor. Turned out great i with this one exception.

 

[Old Fuff]

When your N-frame revolver was made can make a big difference. Prior to 1962 or thereabout the cylinder stop (the part that engages a notch in the cylinder and locks a chamber so it’s concentric to the bore) was tensioned with a coil spring and plunger that was blocked by a screw mounted in the front of the frame, and above the trigger guard. Do not confuse this screw with the front side plate screw.

Starting in approximately 1961 the design was changed. The plunger, spring and screw were eliminated and replaced by just a spring that was nested in the cylinder stop on one end, and a cutout in the frame on the other. While this system was less expensive it had some drawbacks, one of which was that the spring could become kinked or bent when it was reassembled, and then thereafter the stop might move in strange ways.

My earlier post presumed that you had the later system rather then the former, and may – or may not have been in error. This is another instance where a good photograph is worth a thousand words.

Anyway I now think that in addition to the above, part or all of your problem may be too much Cerakote in the cylinder's notches. In the old days of cheaper labor costs S&W assemblers took pains to insure the fit between the cylinder stop ball (that part of the cylinder stop that sticks up through into the cylinder window and goes into the notches in the cylinder) were a snug fit. A coat of Cerakote could have made the fit too tight.

Remove the side plate, hammer and mainspring. Leave or reassemble the rest. Then pull the trigger while watching what the cylinder stop is doing. A light bulb may go on.

 

[mioduz]

When your N-frame revolver was made can make a big difference. Prior to 1962 or thereabout the cylinder stop (the part that engages a notch in the cylinder and locks a chamber so it’s concentric to the bore) was tensioned with a coil spring and plunger that was blocked by a screw mounted in the front of the frame, and above the trigger guard. Do not confuse this screw with the front side plate screw.

Starting in approximately 1961 the design was changed. The plunger, spring and screw were eliminated and replaced by just a spring that was nested in the cylinder stop on one end, and a cutout in the frame on the other. While this system was less expensive it had some drawbacks, one of which was that the spring could become kinked or bent when it was reassembled, and then thereafter the stop might move in strange ways.

My earlier post presumed that you had the later system rather then the former, and may – or may not have been in error. This is another instance where a good photograph is worth a thousand words.

Anyway I now think that in addition to the above, part or all of your problem may be too much Cerakote in the cylinder's notches. In the old days of cheaper labor costs S&W assemblers took pains to insure the fit between the cylinder stop ball (that part of the cylinder stop that sticks up through into the cylinder window and goes into the notches in the cylinder) were a snug fit. A coat of Cerakote could have made the fit too tight.

Remove the side plate, hammer and mainspring. Leave or reassemble the rest. Then pull the trigger while watching what the cylinder stop is doing. A light bulb may go on.

I will strip it down and take some pics and possibly some videos of the action. Thank you. It is the old style of spring with a plunger and a screw.
This revolver was "built" by the owner over 10 years ago where he did a bunch of trigger work and replaced the barrel etc etc. I could just give it back to him and let him figure this out, but I like to learn a little more about revolvers and figure this out for myself while i have the time.

 

[mioduz]

any thing stand out here?

 

[mioduz]

Video
http://youtu.be/BZZ1uMMo5xE

 

[Old Fuff]

The area we need to see most (where the cylinder stop is) is too dark to draw a conclusion, but when you cock the hammer or pull the trigger the cylinder should rotate - and it isn't. Obviously the cylinder stop is not moving as it should, nor is the hand being pushed forward into the cylinder's ratchet.

Post another picture of the side plate when it's upside-down. Also look in the following places for a serial number, and if you find it include it in another post.

On the bottom of the butt.

On the rear face of the cylinder (unless you think the cylinder is a replacement).

 

[mioduz]

The area we need to see most (where the cylinder stop is) is too dark to draw a conclusion, but when you cock the hammer or pull the trigger the cylinder should rotate - and it isn't. Obviously the cylinder stop is not moving as it should, nor is the hand being pushed forward into the cylinder's ratchet.

Post another picture of the side plate when it's upside-down. Also look in the following places for a serial number, and if you find it include it in another post.

On the bottom of the butt.

On the rear face of the cylinder (unless you think the cylinder is a replacement).

Thankyou for your time and help. I tried taking more pictures and videos. Let me know if this helps.
[resize=600] [/resize]
[resize=600] [/resize]
[resize=600] [/resize]

Sw revolver 2: http://youtu.be/D3m4BKR7Db0
Sw revolver 3: http://youtu.be/nJdMyP4Ck34

 

[Sam1911]

[I changed the picture sizes for you 'cause folks can't see them when they're so huge. In the future, add the tags [noparse][resize=600]...[/resize][/noparse] outside of your IMG tags to knock these down to usable size.]

 

[Master Blaster]

Did you check the cylinder stop window in the frame for excess ceracote? Sounds like either that is the problem or the cylinder stop spring, or maybe too much ceracote in the spring recess and its not pushing the stop hard enough.
You do have the correct screws in the right holes? The screw in front of the trigger guard was fitted to be the right length to push on the stop spring.

 

[mioduz]

Did you check the cylinder stop window in the frame for excess ceracote? Sounds like either that is the problem or the cylinder stop spring, or maybe too much ceracote in the spring recess and its not pushing the stop hard enough.
You do have the correct screws in the right holes? The screw in front of the trigger guard was fitted to be the right length to push on the stop spring.

Yes i checked the cylinder stop window in the frame. without the cylinder installed the stop moves up and down freely with little or no friction due to finishing. It does not stick at the bottom or top of the "stroke" and when i push it down springs back immediatly.
The spring does appear to be making adequate pressure on the stop. I assume if it wasnt the cylinder would be more inclined to overly spin. If I back the screw out several turns the cylinder will spin again and overtravel the stop. Yes the screw in the front of the trigger guard is the same one I removed from there.

again thank you everyone for your help

any other suggestions

 

[Old Fuff]

Look at the side plate. When turned upside down you will see a big recess to make room for the hand. Looking from the front, see if they're is a small hole drilled going front to back. If so this is for a spring and plunger that pushes the hand forward against the ratchet. If they're is a hole, and the spring and plunger are missing (or stuck and not pushing on the hand) you will have found the reason for your problem.

Over time, S&W made a number of small changes in their N-frame revolver line. Without having a serial number it's impossible to know when it was made, and what changes were, or were not incorporated. This becomes harder when you have a "parts gun" assembled using parts that may have been made at different times.

 

[mioduz]

Look at the side plate. When turned upside down you will see a big recess to make room for the hand. Looking from the front, see if they're is a small hole drilled going front to back. If so this is for a spring and plunger that pushes the hand forward against the ratchet. If they're is a hole, and the spring and plunger are missing (or stuck and not pushing on the hand) you will have found the reason for your problem.

Over time, S&W made a number of small changes in their N-frame revolver line. Without having a serial number it's impossible to know when it was made, and what changes were, or were not incorporated. This becomes harder when you have a "parts gun" assembled using parts that may have been made at different times.

Let me know if this is of any help. I dont Think the hand is the issue here, i thought it was the cylinder stop not disengaging. but obviosly im not the pro so Im open to any and all suggestions

 

[Old Fuff]

This is not related to your issue, but I notice the hammer block safety mounted in the side plate is broken.

Therefore unless this is fixed (it could be difficult to find a part) be sure the gun owner understands that he/she should always carry the revolver with the hammer down on an empty chamber.

In general, this is a good idea with any S&W hand ejector made before January. 1945. After that it shouldn't be a concern unless someone has tampered with the action.

Since you didn't seem to find the hole in the side plate I previously mentioned I'll come up with another solution in a future post. Looking at your first VIDEO it appears that you can cock the hammer, or pull the trigger in the double-action mode, and the cylinder won't rotate. Try this with the muzzle pointed straight down.

 

[mioduz]

Quick update
I blasted the cylinder to confirm that cerakote buildup was not an issue. (it wasnt) I sanded the cerakote off of the cylinder stop pin to make sure it wasn't binding anything (it wasnt). Loosing my mind I start looking at the pins themselves. Tapping them back and forth very slightly. I was able to tap the trigger and cyl stop pins toward each other and then it started functioning. Over joyed, I put the slide plate on and it was back to being locked up. I beleive this to be because there are pockets in the sideplate for the pins and they are getting pushed back to the original position.

Does that tell anyone anything?

 

[Stony]

It think the gun gods are telling you that an old 5 screw N frame should have been left in it's natural state and not ruined with refinishing.

 

[Old Fuff]

Be careful with sandblasting. This revolver was made at a time when they were literally assembled like a fine Swiss watch. Yes, the various studs (that you call pins) were supported in holes drilled in the side plate to be sure they remained vertical and didn't get bent.

At this moment I believe that you are correct in thinking that refinishing wasn't the original cause of the problem, but rather that something happened during reassembly thereafter. However continued tinkering may result in fixing one, and then discovering you have another. Also be absolutely sure you don't leave any abrasive behind when you reassemble the parts.

 

[Old Fuff]

1. With the side plate off, insert a small punch against the hand at the bottom/front, at a point just above the trigger. Use it to lever the hand backwards a short distance and see if it feels like it's under tension and a spring is trying to push it forward, and can do so when the punch (or whatever) is removed.

2. Watch the ball on the cylinder stop. When you start to cock the hammer or pull the trigger does it go downward and stay down, or does it quickly pop up before the cylinder can turn?

 

[mioduz]

1. With the side plate off, insert a small punch against the hand at the bottom/front, at a point just above the trigger. Use it to lever the hand backwards a short distance and see if it feels like it's under tension and a spring is trying to push it forward, and can do so when the punch (or whatever) is removed.

2. Watch the ball on the cylinder stop. When you start to cock the hammer or pull the trigger does it go downward and stay down, or does it quickly pop up before the cylinder can turn?

Yes the hand is under spring tension forward.

The ball on the cylinder stop does not fall all the way, which is what is binding the action.

 

[Old Fuff]

The ball on the cylinder stop does not fall all the way, which is what is binding the action.

Well you have defined the problem - finding a solution may be harder because of the lack of new parts for a pre-World War Two revolver. You can alter the part you have, but if the alteration doesn't work you may be in deeper trouble. Let me think on this.

 

[Drail]

Spray painting a precisely fitted mechanical device with tolerances in thousandths of an inch - what could possibly go wrong?

 

[Old Fuff]

In this case I don't think the "spray paint" coating caused the problem, but sandblasting first might have contributed to it. Right now what's needed is a constructive solution.