Cylinder not fully locking

[BillBro]

What is generally the root cause, if there is such a thing in the world of revolvers, of the cylinder stop not engaging the stop notch at full cock?

Here is the situation, my M29 has been getting alot of use lately and has performed great. I've shot some high horsepower loads in it sure but not a steady diet, mostly mid to low range stuff and some Specials too. Last week I was practicing my trigger control (yes I had snapcaps in) and was trying to get a little better at staging the trigger for a nice clean break. I was waiting to hear the stop drop into the notch because that is usually my stop point before breaking the shot. It has that "click" sound to let you know its locked up, but I hear no click sound. Try again, no click.

So I cycle the hammer back listening and feeling for all of the actions it goes through and sure enough the stop is not engaging the stop slot on the cylinder. I can just about blow on it and make it move enough to drop it in but it's not doing it on it's own the way it is supposed to.

This is occurring only during very slow cycling of the action. If I pull back the hammer with any sort authority it performs as it should but during a very slow single action scenario it is not locking.

Ratchet and hand all look fine, the spring on the hand seems to have normal tension. Nothing is binding the cylinder that I van see or feel. No peening of the stop notches or stop. Stop spring and stop are both new and from Power Custom. Checked crane alignment is fine too.

I dont get it. As far as I know this just manifested itself out of the blue with no apparent cause. Can anyone offer any advice?

 

[armorer951]

Carry up, or the lack, is checked by slowly cocking the hammer in SA. Late or incomplete lock-up is most often due to wear on the ratchet/hand interface, but many other things can contribute, including dirt and shooting debris in and around components, end shake/out of spec headspace, and yoke misalignment to name just a few.

You advised you have been shooting some heavy loads, so you might try a thorough cleaning, especially of the yoke and cylinder assembly. After cleaning, you will be better able to narrow down and pinpoint the actual issue.

Rear headspace is easily corrected if it is out of specification, and this may solve the problem. Rear gage on a non-recessed cylinder should measure .060" -.068". (smaller is better)
If the ratchet/hand interface is to blame, substitution of a slightly wider hand (+.002"-.003" wider) will likely cure the carry up problems.

 

[BillBro]

Hey armored, thanks for the answers. 29-3 so no recessed chambers and its clean, I mean sideplate off, everything removed and scrubbed clean including the hand window. Like I said angles on the hand and the ratchet pads look pristine. Educate me about headspace numbers for a non-recessed gun. By headspace I assume you mean distance between the recoil shield and cartridge heads. There is basically zero endshake, no perceptible fore and aft movement of the cylinder.

Carry up, yes, that's the word I was searching for. I knew I'd heard it before but couldn't remember what it was called. I mean obviously that is what's happening but again I have a hard time faulting the hand or ratchet at this point. The Good Lord knows I've been wrong many times in my life and may well be again here but this gun has actually been shot VERY little.

 

[armorer951]

I made a mistake on the numbers I gave you above....those are the rear gage numbers for the non-recessed cylinder. (.060" - .068")
It should be measured with feeler gauges, after cleaning and wiping down the area. Measure the space between the rear of the cylinder face and the breechface (empty cylinder) just under the top strap in the general area of the hammer nose bushing.

If you are able, you might also mic the width of your hand at the very top where the "throat" is.....that is the area where the small tooth protrudes slightly forward. That measurement.....probably about .092"-.093" will tell you if your hand is average or "undersized".

 

[BillBro]

Thanks again Armorer951. And I did read your pm too. That may be beyond my comfort threshold but I'll keep it in mind. I'm currently weighing just sending the gun out for a overhaul/actionjob/reblue etc. Just get the gun right and hopefully do something with those sights because those factory ones just never worked for my eyes and now that me and my eyes are much older it's even worse. It has no collector or sentimental value so I dont feel bad at all about mod-Ind the thing. I just want a solid shooter.

I'll take those measurements tonight and get back to you and again, thanks. I really need some of those Kunhausen manuals or whatever his name is.

 

[.38SuperMan]

Funny that I ran across this thread. In the last couple years I've had several revolvers with timing issues. Several were new and had the problem straight out of the box.

My first experience with timing was with a used but well cared for 625-2.

Second was my wife's used 317 Smith.

Third was a new Ruger Blackhawk convertible 357 straight out of the box.

Fourth was a brand new straight from the box Cimarron Custer model 45LC.

Fifth and it happened today on its second range trip, a brand new 3" Colt King Cobra. The KC was so bad it was building lead up on the forcing cone and locking the cylinder up. I guess I've shot about 200 mild 38's and no 357's through it. At one point I could rotate the cylinder backwards when the hammer was cocked. Bad!!! Well anyway it's headed back to Colt for a fix.

The moral to the story, **** happens so don't let it get you down and no manufacture is exempt from problems.

 

[.38SuperMan]

Here are some of the spent cases from when timing failed. Note how off center some of the primer strikes are. It actually amazes me that all of them detonated.

I examined the revolver carefully and didn't see any indication of what would cause it. The gun hasn't been disassembled or abused in any way. I've only shot mild 38's in it.

I had my model 15 Smith with me and shot the same ammo in it with no issues.

It'll be interesting to hear what Colt says.

Edit: when the problem happened my first thought was high primers or bullets that walked out and jammed the cylinder but on inspection none of the 200 rounds, different loads and bullet profiles had high primers or had walked out of the case due to recoil.

Could this be a broken hand? The primer strikes are inconsistent. The ratchet didn't appear to be damaged and saw no indication of why it would happen.

I thought about dirt but I cleaned it thoroughly after my first range trip.

Your thoughts are appreciated.

 

[armorer951]

In my experience, Colt double action revolvers like the one you mention don't "carry up" in the same way as Smith and Wesson's do.

If a S&W revolver is properly fit, the cylinder will (should) carry up fully and lock in place before the hammer falls in both double and single action.

Colt's actions on the other hand, do not always carry up fully in SA or DA, and the cylinder does not fully lock prior to hammer fall, particularly in double action. Full lock up on many of these revolvers occurs during the completion of the trigger pull phase during hammer fall. This, I believe is due to the differences in the design of the hand and ratchet parts, and the fact that the Colt hand is not in a frame slot per se, but is confined in the space between the frame, internal parts, and the sideplate.

Perhaps your Cobra needs a slightly longer hand, (cylinder lock up is late) or there is another problem that is contributing to the carry up/lock up inconsistencies.

Please note, the previous comments are my own opinion based on experience. I am not a Colt armorer. Colt doesn't have an armorer's training program.

 

[BillBro]

I discovered another issue that may or may not have some bearing on my timing issue? In handling the 29 the other day during cleaning post range trip I felt the front of the cylinder moving left to right, not alot at all but its definitely there. In moving it gently back and forth I saw a gap develop between the frame and the crane/yoke, again very slight but there. I further saw that the exttactor rod end that locks to the detent/ plunger was a bit rough and the plunger end itself is not at all what it seems it should be, round, to mate to and lock into the end of the extactor rod, in fact it is not locking the front of the cylinder at all. The plunger pinned into the shroud is just moving around in the end of the extractor rod.

Is this a possuble contributor to the timing going out of whack? I dont know but I do know I dont like that the cylinder is not fully locked in place as it should be. Ive already removed the pin, plunger and spring and the gun is now also fully disassembled sans cylinder lock and spring.

The end of that plunger or detent or whatever it is called looks like it was not shaped properly at all to be able to perform its intended function and I really believe it needs replacing aling with the extractor rod because of the angles on the end of the detent it is now pretty badly worn. Man, its one thing after another with this 29.

Does Numerich or Midwest have these parts? If anyone has these to spare Id buy them.

By the way, if anyone knows of a worthy Smith smith in the DelMarVa area let me know olease. Im thinking I should just send it to a professional for a complete tyne up. I know S&W is always an option too but if I can get a local guy Id prefer that.

 

[armorer951]

Sorry, this is an opinion again, but the front locking bolt and extractor rod interface is one of the most difficult areas to fit correctly on the entire S&W revolver.

The complex goal for this particular interface is that it should be fit to reduce some of the lateral stress on the cylinder and yoke, it should not interfere with the "ease" of the opening and closing of the cylinder, and to keep the cylinder assy in perfect alignment as much as possible.....all this, mind you, without directly impeding the rotational movement of the cylinder assembly. This is a tall order, believe me.

Because of this, there are wide variances in the individual fitting of these parts among different models and individual guns. When they are brand new out of the box, some work great, and some not so well. Wear and tear then has it's inevitable effect on the parts....which means of course that it goes down hill from there.

If you're concerned, you should have this evaluated by your trusted and trained local gunsmith, if you are fortunate enough to have one close.

Evaluating this kind of thing without an actual exam is like trying to do surgery over the phone. (AKA: impossible)
Based on your description though, and without photos, I would say there isn't a problem at this point. This interface was never designed to be "inflexible" when stressed by intervention (pushing/pulling) from your hand/fingers.

 

[BillBro]

Again Mr951, thank you. I do have pics of both parts and will work on getting them posted here as you seem to fairly consistent in your monitering of the boards thankfully. The lateral movement of the front of the cylinder and the resulting gap at the frame/yoke is a recent thing. I handload alot, like everything I fire is handloaded, well below factory levels Im sure of this so I dont believe Im abusing the gun any undue amout. And, Ive not noticed this wear on the end of the extractor rod before, and it really stands out against the black of the rest of the part, the wear being a bright shiny silver.
Are you a fan of the ball/detent lock-up in the frames? Are they helpful at all in your opinion?

Quality gunsmith in my area????? Nobody with a reputation that I know of. I frequent a sporting clays range nearby and they have a guy who works on Smiths , he left town until sometime early next year on the 28th of last month, I called him on the 29th to talk with him about it. I spoke to another "gunsmith" who says he has worked on many revolvers but his business as far as Ive heard consists of mainly doing Cerakoteand hydrodipping and pinning muzzle devices on ARs. I explained my issue and he did seem to ask the right questions and named the right parts as possible culprits, hand, ratchet etc. So maybe Ill have him take a look-see and see what he says. Id like to just find someone local to just give the gun a thurough tune and to spec because this thing has been a headache.

I appreciate your wisdom and experience and educating me in the ways of S&Ws and I will get the pics up as soon as I can.

 

[BillBro]

 

[.38SuperMan]

In my experience, Colt double action revolvers like the one you mention don't "carry up" in the same way as Smith and Wesson's do.

If a S&W revolver is properly fit, the cylinder will (should) carry up fully and lock in place before the hammer falls in both double and single action.

Colt's actions on the other hand, do not always carry up fully in SA or DA, and the cylinder does not fully lock prior to hammer fall, particularly in double action. Full lock up on many of these revolvers occurs during the completion of the trigger pull phase during hammer fall. This, I believe is due to the differences in the design of the hand and ratchet parts, and the fact that the Colt hand is not in a frame slot per se, but is confined in the space between the frame, internal parts, and the sideplate.

Perhaps your Cobra needs a slightly longer hand, (cylinder lock up is late) or there is another problem that is contributing to the carry up/lock up inconsistencies.

Please note, the previous comments are my own opinion based on experience. I am not a Colt armorer. Colt doesn't have an armorer's training program.

Thanks very much! Your thoughts on this are very logical.

Observing the three Colt revolvers I own, all three appear to lockup just after the trigger is pulled. As the trigger is pulled the cylinder rotated a couple of degrees and locks up. Obviously my King Cobra isn't locking.

Thanks once again!

 

[Hondo44]

BillBro;

#1. Recognize that the front locking bolt for the extraction rod is not supposed to be symmetrical. It has a bevel ground on the side facing the extractor rod. That bevel acts like a cam to assist the rod in retracting the bolt forward to allow the rod to close. Your bolt looks normal.

#2. About your original issue with the cyl stop: If your not hearing a click for the cyl stop popping up to hit the cyl, and probably not seeing the stop pop up, I'd start my troubleshooting there. It would not be a timing issue.

Open and swing the cylinder all the way open, now with your left hand, push and hold the cyl thumb piece all the way to the rear.

This will allow you to test by cocking the hammer single or double action and observing the cyl stop without the cyl in the way. If the stop does not pop up consistently, there's some interference you need to look for:
It could be fouling from a lot of shooting as was mentioned above.

But since you mention non-factory parts (Power Custom) were installed, I suspect they may be installed w/o proper fitting; who installed them?

Maybe the fit of the stop thru the rectangular hole in the frame is too tight. Clean out the rectangular hole well and put some lubricant in the hole and on the stop. Now do your test again. If the stop functions properly or more consistently, or the problem is solved, you've found the issue: remove the stop and flat polish the sides for more clearance in the hole.

If the function didn't improve with cleaning and lubrication, pull the side plate and function the hammer to test for internal interference of the stop with other parts. It's released to pop up by the front hook on the trigger; check there. Make sure the trigger returns all the way forward after after pulling it.

Caution: don't function the hammer excessively or heavily with the side plate off because the hammer and trigger pivot studs are not supported by the side plateplate when it's off.

Let us know what your test results are,

 

[WR Moore]

Back in the day I worked on exactly one Colt revolver. After I got it out the door, I refused to touch another. The lock work was reminiscent of Rube Goldberg gadgets-(you younger folks need to look that one up on Wiki) at least to me. I agree that the cylinder doesn't reach final alignment/lockup until the trigger is all the way back and the hammer is on the way down.

I've no idea whether the new Colts use the same antiquated system.

 

[Protocall_Design]

I think the Colt Python is one of the best looking revolvers ever made. Having owned 4 Pythons in the 70s, shooting them for many thousands of rounds, and doing action jobs on all of them, I got to know them very well. There are 5 parts of the lockworks that are all interdependent on one another. If you change something on one part, you have to go around and change the other 4 to match. If you overdo one of those a little bit, you have to go around and change the OTHER 4 to match THAT. It can turn into a situation of (seemingly) endlessly going around in circles chasing your tail.

Colt parts have always been expensive and hard to come by, much more now than ever. On the other hand, S&W is a lot easier to work on, and parts are readily available for a reasonable price.

 

[BillBro]

Hondo, thanks for the many words however new cylinder stop and spring and window were all given their due attention and all harmoniously worked together for several years and many hundredz of rounds. Window was relieved a bit on the frame side, not the sideplate side , top edges given a slight radius and polish and it was fitted to the smallest(tightest) stop notch with just enough room to roll out of the notches. So yes, it is functioning correctly it is just not fully locking into the cylinder stop notch at the very end of the cycle, i e just before the hammer is to fall. And as I said its just a whisker from dropping into place, and I do not see any wear on the hand its nice and crisp as it always was not any abnormality of the ratchet. It certainly has me puzzled. Ive also completely stripped and cleaned the thing and looked at every single part and see nothing, but obviously I am missing SOMETHING! Oh and about the extractor rod and bolt, yep, I learned that too, the shape of it I mean and it makes perfect sense.

 

[armorer951]

Have you measured the width of the hand the "gunsmith" replaced, and compared it with the width of the hand that is currently installed? Are you checking carry up with empty casings installed in the cylinder?

Reading your description of the problem it sounds like the current hand is not wide enough.

 

[Hondo44]

Hondo, thanks for the many words however new cylinder stop and spring and window were all given their due attention and all harmoniously worked together for several years and many hundredz of rounds. Window was relieved a bit on the frame side, not the sideplate side , top edges given a slight radius and polish and it was fitted to the smallest(tightest) stop notch with just enough room to roll out of the notches. So yes, it is functioning correctly it is just not fully locking into the cylinder stop notch at the very end of the cycle, i e just before the hammer is to fall. And as I said its just a whisker from dropping into place, and I do not see any wear on the hand its nice and crisp as it always was not any abnormality of the ratchet. It certainly has me puzzled. Ive also completely stripped and cleaned the thing and looked at every single part and see nothing, but obviously I am missing SOMETHING! Oh and about the extractor rod and bolt, yep, I learned that too, the shape of it I mean and it makes perfect sense.

If you're sure the cylinder is revolving all the way into position for the cyl stop notch to align with the cyl stop (by cocking the hammer single action and testing if the cyl turns a little more with your hand), then the next suspect part for me is the cyl stop spring. It may be weak or slipped part way out of position.

What dash # is your 29? Does it have the spring retaining screw in front of the trigger guard or not?

 

[ms]

If your extractor star is a little loose, and your snap caps a little small, having actual cartridges in may fix it. Next time you're at the range see if you can duplicate the failure to carry up with live ammo, or empty cases. Are the little pins that align the star in place?

 

[BillBro]

It does and yes they are. It does it with live ammo and pins are both there.

I know, I know. This is beyond me obviously. Thinking logically, or as logically as I am capable, Ive tried almost everything everyone has suggested. Ill happily post pics of anything anybody needs/wants to see.

I have spoken to a guy who says hes a gunsmith about it to take a look but hes out of town on a bear hunt right now. Id live to be able to fix this myself tho. Its gotta be something simple. And besides, U just refinished the sticks for it and theyre beautiful but I cant punt them on a broke@$$ gun. That would just be a shame.

 

[Hondo44]

So yes, it is functioning correctly it is just not fully locking into the cylinder stop notch at the very end of the cycle, i e just before the hammer is to fall. And as I said its just a whisker from dropping into place....but obviously I am missing SOMETHING!

Yes, you are: the cylinder does not "carry up"!

It's the teeth on the cyl extractor star, a very common issue.

CARRY UP SUMMARY:

When the cylinder is a few thousandths short of advancing completely to lock up, known as "carry up", peening the teeth to 'upset' metal on the extractor star is much simpler than finding and fitting a new hand.

The hand is made of harder steel than the teeth since it has six times the contacts of each tooth, and this is a typical result after many rounds of shooting. That's why I would not install a new hand, it already has the advantage.

With the cylinder open in a vertical position, use a flat tipped punch to very gently peen each of the offending teeth of the 6 ratchet teeth on the rear vertical surface of the edge contacted by the hand. One tap on each tooth will usually do it and the gun will function perfectly for another 20+ years. I've fixed so many that way I can't count them.

Caution note: Before peening, first assess for excessive cyl end play and/or yoke end play. These should be addressed before any peening is attempted. Also be sure that neither the trigger or hammer stud is not loose or broken, or that the extractor rod or particularly the yoke are true and not bent. If more than gentle tapping seems required to upset the star teeth, to the point of being obvious, there may be severe wear or other issues involved.

DETAILED CARRY UP REPAIR:

You have a "carry up" problem. You can fix it faster than you can read the explanation and 'how-to' below w/o any new parts.

The issue is a failure to "Carry Up". In other words the hand does not carry the cyl far enough to lock up within the normal cycle distance of the hammer travel. Usually it doesn't show up in DA shooting because of the momentum of the faster cyl rotation.

Based on your assessment and comments, I believe Pat Sweeney's "Gunsmithing Pistols & Revolvers", 2nd Ed.(2004), pp.219-220 is the most sensible, perfectly good solution, what I would do and have done many times, what S&W factory trained smiths have done in similar situations, and also what members on this forum have done successfully after reading about it, which is:

Peening the ratchet tooth (or teeth) to correct timing/cyl 'carry up' is simple.
Replacing and fitting a new hand may fix your problem and may not, but the hand is not likely needed or at fault. It's the harder part compared to the cyl teeth.

The flat surfaces of the teeth facing you when looking at the rear face of the cyl are where to peen. The tooth at about 3 o'clock is the next to be engaged by the hand (when cyl is closed) to advance the chamber to the right of the one at 12 o'clock, into firing position. The cylinder turns counterclockwise so the hand will engage the 'bottom side' of that tooth. The flat surface facing you is where to peen, on the edge right above the bottom side of the tooth. No need to take the gun apart at all. I lay the gun on a padded surface on its right side, muzzle pointing to the left (I'm right handed) with cyl propped open with a rolled up shop cloth.

If you're worried about force to the yoke and frame, I'm afraid that you're envisioning TAPPING TOO HARD. Just a very light peen with a small hammer and flat tip punch is all that's needed to 'upset' the metal. The ratchet teeth are not hardened! This takes finesse, not force.

And by laying the gun on a padded surface without restraint as I described, it's allowed to move when the punch is tapped with the hammer, mitigating any force to the yoke and frame.

You may not even see the metal 'upset' from tapping the punch and it can be enough to solve the problem. One light tap with a small light hammer and flat face punch then close the cylinder and try it. If the cylinder doesn't 'carry up' or even if it does C/U but still has too much 'looseness' when fully cocked, give the tooth another tap. You can do all six teeth, or just others where there's looseness with the chamber in firing position when the hammer is cocked.

Rough handling/constant double action rapid fire can accelerate the teeth deformation but it did not happen overnight, and now you have another many years of shooting before it'll need anything more, depending of course on how much you shoot the gun. I've never had to do the same gun twice.

If you peen too much and the cylinder carries up too far that puts cocking the hammer in a bind or the bolt 'jumps' out of the cyl notch, not a problem, peen the surface that the hand contacts and push it back.

I would not put up with a carry up issue especially when it's so simple to fix.

Hope this helps you,

 

[armorer951]

The factory approved cure for the carry up issue was discussed in comment #2 above. My apologies to Mr. Sweeney, but the S&W factory has never taught or used ratchet peening as an option for repair of this malfunction.

The correct, approved repair for this particular problem is to simply substitute a slightly wider hand for the one that is currently in the gun. If the ratchets are worn to the point where proper function cannot be restored by replacing the hand, or if an oversized hand is already in the gun, then a new extractor assembly will need to be fit.

 

[BillBro]

Please, I dont want to start any arguements between anyone. Regardless, I dont think I would have the sack to be tapping on the ratchet teeth, Id probably just end up making it worse or at best not fixing anything. Ill go ahead and order an oversized hand for the guy I may let work on it for me. Gonna have to bend this guys ear a bit to find out a little about him first.

 

[Hondo44]

The factory approved cure for the carry up issue was discussed in comment #2 above. My apologies to Mr. Sweeney, but the S&W factory has never taught or used ratchet peening as an option for repair of this malfunction.

The correct, approved repair for this particular problem is to simply substitute a slightly wider hand for the one that is currently in the gun. If the ratchets are worn to the point where proper function cannot be restored by replacing the hand, or if an oversized hand is already in the gun, then a new extractor assembly will need to be fit.

You're absolutely right about the factory of course. But we have to keep in mind that the factory has high liability concerns with its product repair. Therefore their policy differs from professional gunsmiths. S&W replaces parts and basically repairs the guns like new guns are assembled, they don't do repairs "per se". They will not and cannot do 90% of what even the best professional custom revolver smiths can do. S&W has assemblers, not skilled gunsmiths.

 

[Hondo44]

Please, I dont want to start any arguements between anyone. Regardless, I dont think I would have the sack to be tapping on the ratchet teeth, Id probably just end up making it worse or at best not fixing anything. Ill go ahead and order an oversized hand for the guy I may let work on it for me. Gonna have to bend this guys ear a bit to find out a little about him first.

No arguments here, we're all friends who share knowledge.

So many on this forum have repaired this issue on their guns this way and were amazed at their success and how easy it was. Everyone needs to stay in their comfort zone though.

 

[BillBro]

I just went ahead and bought a PC oversized hand and will have it fityed to the gun and hope that solves the issue, then I might sell it.

 

[armorer951]

Just a heads up concerning the Power Custom hands.....they are very high quality, but oversized to well over .100", and in most situations, will not fit into the hand window in the breechface. If you check your current hand with a micrometer, you may be able to substitute a new S&W oversized hand, or one that is .002" - .003" wider than your current one, with very little modification and/or fitting. (Instead of the Power Custom hand)

When fitting one of the PC hands, it's always best to carefully remove material from the hand (plate side) if at all possible, to reduce thickness, rather than opening up the frame window. New hands are cheap compared to a vintage frame.

 

[handejector]

The factory approved cure for the carry up issue was discussed in comment #2 above. My apologies to Mr. Sweeney, but the S&W factory has never taught or used ratchet peening as an option for repair of this malfunction.

The correct, approved repair for this particular problem is to simply substitute a slightly wider hand for the one that is currently in the gun. If the ratchets are worn to the point where proper function cannot be restored by replacing the hand, or if an oversized hand is already in the gun, then a new extractor assembly will need to be fit.

You're absolutely right about the factory of course. But we have to keep in mind that the factory has high liability concerns with its product repair. Therefore their policy differs from professional gunsmiths. S&W replaces parts and basically repairs the guns like new guns are assembled, they don't do repairs "per se". They will not and cannot do 90% of what even the best professional custom revolver smiths can do. S&W has assemblers, not skilled gunsmiths.

I get it now. The Factory lacks the skill required to fix a gun with a hammer.
Instead, they insist on using the archaic method of installing a properly fitted part.
They need bigger hammers!

 

[stu1ritter]

As an Army gunsmith I would have called Hondo's repair a field fix and Armorer's a depot level repair. Both valid.

Stu