Cylinder Turn Lines

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I've passed on purchasing several revolvers because the cylinder turn lines looked more like deep "gouges" around the circumference of the cylinder rather than just shallow scratches in the bluing. What causes the excessive gouging? Is it a timing issue with the cylinder stop, or some other problem? Besides being unsightly, does it indicate a significant concern with the safe operation of the firearm? Would you buy a revolver with a gouged cylinder?
 
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It depends on many things.

Make & Model of a revolver.....

Regarding S&W's, any 27-4, 27-5 and up will get heavy turn lines on them

Ditto 25-7, and 25-9's as well as 29-5's and up. When I say and up, I am referring to engineering changes. I would not worry about a heavy turn line on these models.

As far as a deep gouge, that shouldn't be the case at all.

on the aforementioned revolvers, you'll get a heavy bright shiny turn line, thats because the cylinder stop spring is heavier in those revolvers than the previous models.

I've been told that on Colt SAA revolvers, a heavy turn line will indicate there is something wrong in the action.

On a Smith revolver, I look at finish wear on the recoil shield, the ejector rod, and I look for flame cutting above the forcing cone, on the top-strap.

Also, the normal check for timing, end-shake, and side to side play in the cylinder.

The turn ring is a low hanging red flag for me. On earlier revolvers, yes its a sign of being cycled, checking the other areas will indicate if the gun is high mileage.
 
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The Colt revolver action is far different from the S&W or most other revolver actions. A turn line on a Colt is an indication of improper handling or a timing problem with the cylinder stop being released too early and dragging on the cylinder. Turn lines on S&W revolvers are normal and simply indicate that the action has been cycled enough to cause the stop to wear the finish on the cylinder.
 
I've seen a few Chiefs lately with the apparent "gouge" you mentioned, almost as though the cylinder had been run through a lathe. I have no idea why that happens.

I don't have a revolver without a turn line so obviously they don't bother me, but I find the gouge most off-putting.

Bob
 
Burr or sharp edges on some cylinder stops? Higher hardness on some stops? Lack of lubrication?
 
I'm no expert, but my theory is that a revolver can be timed to keep the turn line to a minimum. But it requires expertise and fitting time. I noticed that my S&Ws from the 1950s have virtually no turn line while one made in 1980 had a groove worn in the cylinder from the bolt riding on it. More craftsmanship 65 years ago than 25 years ago. What do they look like now?
 
In my brief learning curve of Smith revolvers,
The turn line will be present on every gun, unless it's never been cycled. It's a fact of how designed.
Guns with a heavy turn line could have all the causes listed by roller delayed previously.
Imho, the 2 main causes are a burr on the foot and lack of oil.
It is relatively easy to help them though. You'll need a few tools and Kuhnhassens book.
Excellent results are attainable from an afternoon of tinkering.
I dont pay to much attention to a heavy turn line, as GRT stated, look at other areas when inspecting a gun.
If I'm interested in a gun, I'll use the heavy turn line as a bargaining chip. Many lgs really dont know much about older revolvers.
 
The Colt revolver action is far different from the S&W or most other revolver actions. A turn line on a Colt is an indication of improper handling or a timing problem with the cylinder stop being released too early and dragging on the cylinder. Turn lines on S&W revolvers are normal and simply indicate that the action has been cycled enough to cause the stop to wear the finish on the cylinder.

Not sure what this means.

Both actions rely on the cylinder stop being pulled down by the trigger and then released at some point.

The original Colt DA system (not the later models like the Anaconda) is a bit less robust than the S&W (which hasn't changed much since the first solid frame models) so if anything it might wear a bit faster, but as long as it locks up properly there's nothing to worry about.
 
The Colt revolver action is far different from the S&W or most other revolver actions. A turn line on a Colt is an indication of improper handling or a timing problem with the cylinder stop being released too early and dragging on the cylinder. Turn lines on S&W revolvers are normal and simply indicate that the action has been cycled enough to cause the stop to wear the finish on the cylinder.
Not sure what this means....
When a Colt DA revolver is properly timed, the stop drops in the lead to the notches - not on the side of the cylinder like a S&W. If you're careful when closing the cylinder of a Colt to align the stop with the notch, you won't develop a turn line (except in the lead). Closing the cylinder arbitrarily and turning it until it engages the notch is abuse/mishandling and will create a turn line in short order.
 
Closing the cylinder arbitrarily and turning it until it engages the notch is abuse/mishandling and will create a turn line in short order.
I would imagine any Colt revolver used in actual combat or similar competition is going to be abused this way.
 
This is one area that Colt's design is better than S&W's. On a Colt DA revolver the bolt* is retracted completely from the cylinder until the lead, then it recontacts the cylinder to engage the notch.

*Colt nomenclature.
 
I would imagine any Colt revolver used in actual combat or similar competition is going to be abused this way.
They will develop holster wear too, but those are tools rather than collectibles.

I’m referring to the way a knowledgeable shooter-collector would handle a desirable gun. Carry/combat guns are a different story. With a little care, you can put thousands of rounds thru a gun and still have it look near new. Improper care and mishandling can just as easily destroy the value of an unfired gun.
 
THE CYLINDER "STOP TRACK" STORY:

Two things are true: The cyl stop is designed in such a way as to eventually leave a cyl ring half way between each pair of cyl lock notches. And any revolver can be fine tuned to avoid making a cyl ring although with anything but conscientious handling it will usually develop anyway.

The cyl turns counter clockwise, and the left edge of the cyl bolt is the leading edge which would appear to be the edge that causes the cyl ring. However there's more to this than may be immediately apparent.

As we know, the Smith cyl lock bolt is centered in the frame and the upper surface is square (not slanted like a single action which uses an offset cyl bolt). Therefore the flat top surface of the DA bolt meets the cyl surface almost squarely. Almost because, considering the curvature of the cyl, technically only the center of the bolt's surface contacts the cyl. The top surface of the bolt rubs against the cyl, not the left edge. That's why roughness or tool marks in the surface of the bolt does the line inscribing. The left bolt edge never has the opportunity to contact the cyl surface, certainly not by itself to cut into it.

So the leading left edge of the cyl bolt also encounters the cyl notch approach ramp first. The approach ramp is on an angle lower than the surface of the cyl, right? Therefore the left edge gets even farther from contact with the cyl as it enters the ramp. Then the center surface of the bolt loses contact as the right side half of the bolt surface rides over the edge into the ramp until, at the beginning edge of the ramp, the right edge alone makes contact with the cyl.

That's when a sharp right side edge of the bolt in contact by itself starts cutting at the entrance edge of the approach ramp and continues its cutting action all the way across the approach ramp, the bolt continuing to rise as it gets deeper until the right bolt edge slips over, cutting the right notch edge as it goes, finally popping up into the notch.

Hence the importance of breaking the knife edges of the bolt, but particularly the right side edge! Breaking the knife edge on the left edge of the bolt is good too and helps prevent cutting, rounding or chipping of the left side edge of the cyl notch when the gun is cocked. Stainless guns are much more susceptible because SS is softer than carbon steel, and gouging of the cyl surface is common.

CYLINDER STOP TRACK MITIGATION:

You'll see in other posts, that not all care about this issue and are quick to tell you. The cylinder line scribed by the cylinder stop is about the most obvious sign of wear. Not just a sign of shooting but also of cycling, opening for checking, or loading and unloading. If you aren't already aware, there are two things that you can do to mitigate or minimize cyl scribing:

1st HANDLING:

When you close the cylinder on a double action, with your left hand grasp it around the bottom of the frame with thumb and forefinger each in the cylinder flutes opposite each other. Position them at 3:00 and 9:00 o'clock just as the cylinder locks into place. The cyl stop will lock into the stop notch w/o having to rotate the cylinder with cyl stop rubbing on its surface. This will become a habit whenever you close a double action cylinder and you'll no longer have to think about doing it. This will prevent a FULL CYLINDER RING and limit it to an interrupted ring, and show a properly handled revolver.

2nd POLISHING THE CYLINDER STOP:

To mitigate “cylinder stop track" for all SA and DA revolvers - preventative action you can take and the 1st thing I do on any revolver of mine, new or used is pull the cylinder (or open it, in the case of DAs) and polish the cylinder stop!

Many come with file marks just waiting to carve out a line and groove in your cylinder finish! Stainless guns are the worst, they can gouge like aluminum. I have to look at the cyl stop surface with a 10 power jeweler's loop or my 10x gunsmith glasses (which are excellent eye protection as well) to truly see if the stop needs polishing. What looks good to my naked eye can be bad enough to mark up the cylinder. The sharp stop edges can really do damage and don't need to be knife edge sharp to function properly with a nice tight lock up.

Swing out or remove the cyl and I mask off the frame and breech face all around the stop with blue masking tape because I use a Dremel tool and it can slip off the stop. I wear my gunsmith 10x glasses and look for any irregularities. If there are any marks, I use a VERY FINE abrasive wheel in the Dremel tool to polish out the file marks, etc., but I don't touch the sharp edges or change the contour of the bolt unless it needs slight re-contouring to center it in the cylinder notch leads. If no file marks, I go straight to polishing.

With a little felt buffing wheel in the Dremel and white rouge (used for stainless steel) I put a mirror finish on the top surface. This is when I also address the sharp edges; I leave them nice and square but just dull the knife edge with the buffing wheel and the rouge. And I don't overdo it.

It only takes 10 minutes including masking and cleanup.

The fine abrasive wheel I advocate only for removing tool marks in the surface of the bolt which can be pretty rough, works very well in experienced hands and it's quicker; about 5 seconds. But never for breaking the sharp side edges. Another 5 seconds with the cotton polishing buff wheel w/rouge will give a mirror finish to the bolt surface and break the sharp side edges at the same time w/o ever focusing directly on the edges with any tool.

So I feel everyone is free to make their own choice of tool usage based on their own experience. If they feel more comfortable to do it by hand I don't tell them not to and I also don't tell them not to use a Dremel tool.

3rd CHANGING THE CYL STOP TIMING:

Yes the timing of the cyl stop release can be changed by refitting the bottom of the stop and the trigger front lever interaction to not release the stop until it drops into the approach ramp to the cyl notch, but it is not recommended by gunsmiths; also see below.

S&W’S RESPONSE RE: THE CYL STOP TRACK:

Photos of documentation in this thread post 21: http://smith-wessonforum.com/s-w-ha.../342287-model-29-turn-line.html#post137516542

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Photos by Gun 4 Fun

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Photos by Gun 4 Fun
 
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My 27-7 has never been fired and has a turn line and I wish it didn't.
 
"With the tremendous increase in the speed of firing..."

Must be too many folks were watching gangster movies....
 
First of all, the turn line produced by the cylinder stop is perfectly normal, and cannot be avoided on a revolver that is used for the purpose for which it was created.

Secondly, S&W does not recommend polishing, or any other modification of the ball of cylinder stop, with the exception of crowning the edge on the high side of the top of the stop ball. Any other polishing or modification is unnecessary, and can damage the stop, or cause malfunctions.
The top of the stop is not square, as some have stated, but is on a very slight angle, with the leading edge slightly higher. The high side of the stop ball is on the "frame side" of the stop. This very sharp edge, if there is one, is the only point at which the stop contacts the face of the cylinder, and can be polished with crocus cloth or ceramic stone. (the high side of the stop is facing away from you when you look into the action after removing the sideplate)
Modification of this edge should be done after removal of the stop from the frame, and the purpose should be to polish the sharp edge or "crown", and not to remove material. Polishing here can often mitigate the turn line, and make it less noticeable as inevitable wear and tear occurs.

Replacement cylinder stops will often require fitting, which usually includes careful fitting the stop ball's width to the smallest cylinder notch..... cutting the slot in the stop just above the bevel.... and or the bevel itself, in order for the stop to work (time) properly as it interfaces with the nose on the trigger. Material may have to be removed from the adjustment step on the top surface of the stop body, to allow the stop's upward movement to be increased or "let out", as the factory refers to it, to insure proper depth of engagement into the cylinder slots.
After the stop has been fit properly, the only factory recommended modification would be to crown the sharp edge on the "high" or frame side top edge of the ball.
 
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