629-3 timing issues

[Dieseltech56]

Hey guys, I've been undertaking a little bit of my own gunsmithing lately and it's been a huge learning experience for sure. The more I know what to check for the more I've been finding out about used guns I look at and even some of my own guns that I never knew had issues.

My latest issue found was with my own 629-3 5 inch classic. I bought this gun a few years ago and the thing looked so clean I didn't think there was any way it could have any problems. Well one day recently when I was re oiling it I found it wouldn't lock up on 2 chambers when cocking slowly single action. I tried to convince myself there wasn't an issue but deep down I knew there was, all my other N frames locked up great.

I had to figure out what to do. I marked the 2 ratchet teeth that were the problem and looked at them closely, you could see they were much more worn than the others. I really thought about sending it back to S&W but I was worried about how they would handle the problem. The 629-3 has the old style extractor with the 2 locating pins. S&W hasn't used this extractor for probably 25 years so the chances of them having that part or even the whole cylinder I thought were slim.

The 2 offending teeth are at 2 and 4 o'clock

I also thought about installing a new cylinder with the new style ratchet. Midway has these in stock. All the pictures I have seen of the newer classic cylinder the scallops on the front don't look the same and all the lines look much more rounded. I wanted to keep this gun looking as original as possible. That is a big pet peeve of mine.

Okay so the cheapest thing I could do was order an oversized hand. Not the power custom one, just the factory S&W. I did not want to get into trying to fit the power custom one unless absolutely need be. The S&W oversized hand came in and it measured out at .098". That sounded good, I have some K frame hands that are .093" and .095". When I disassembled the gun though much to my horror it already had a .098" hand in it! That sealed the guns fate, this was going to be a much bigger project.


So now what to do? I needed a new ratchet or a hand that required extensive fitting. I do not at all like the idea of filing the hand window to fit a hand that once the ratchet is worn out again you are done.

However no old style ratchets are anywhere to be found and that left me on the hunt for an old style cylinder with ratchet. I found a blurry looking one on Gunbroker for $85. I was thinking this thing is probably all dinged up but really I just wanted the extractor, it was a risk but what else could I do? I ordered it and it came in last week, it was a little scuffed up but not bad and the teeth looked a lot better than my old one. I had no idea that the extractor would not just swap from cylinder to cylinder, neither extractor would fit either cylinder. Shoot! Now I was going to have to fit a whole cylinder rather than just an extractor. I had to spend about an hour on this thing with gray very fine scotch brite just to get it looking like the old one. Once it did I put the rod and springs on it and snapped it into place.


Endshake was great but it did not like the .098 hand. The gun would not cock, there was no room for the hand to slip past the teeth on the new ratchet. I took my new hand and about 5 sheets of 600 grit and went to town. It probably took me well over an hour to get that hardened hand filled down to .096. I checked it at each thousandths removed and at .096 it was really getting close, only a small hitch at the end of the DA pull. I do not have any files to touch up the ratchet teeth so that was out of the question, I did not want to mess with my new one regardless.

I was getting really tired of filing this hand and since I was approaching the thickness of a standard hand I stopped for a minute and thought about the situation. I have over 10 N frame post endurance guns so why wouldn't I just try a hand or two from them and see what thickness works best? I grabbed one from a 629-5 and it measured out at .0935. Stuck it in the gun and everything worked great except one chamber would not lock up! At least I had a range to work with now. .096 was too tight, .093 was too loose.

I also noticed one other thing too, the .093 hand sat closer to the trigger than the oversized hand I was trying to fit. Came to find out that the shorter of the 2 pins sticking out of the hand is responsible for that, the one in the oversized hand was sticking out .020" further causing my hand to sit crooked in the hand window.

Once I filed the pin down and worked the hand just a little bit more down to .0955" it sat in the window perfect and now carries the cylinder up great. I must have disassembled this gun 10 times in the last month and I'm finally happy with it. Thanks for reading.

 

[Hondo44]

Glad you got good results. Here's the usual 5 minute fix for future reference:

CARRY UP SUMMARY:

When the cylinder is a few thousandths short of advancing completely to lock up, known as "carry up", peening the teeth 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 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.

I have more detail if you’re interested in this repair.


DETAILED CARRY UP REPAIR:

The issue is called INCOMPLETE "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 doesn't show up in DA 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, a perfectly good solution, what I would do, what I 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 this, 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.

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 punch is all that's needed. 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 deform 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 wear but it did not happen overnight, and now you have another 20+ years of shooting before it'll need anything more, depending of course on how much you shoot the gun. 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.

 

[Dieseltech56]

Thanks Hondo! I did try to peen the teeth but I made very little progress and I was worried I'd mess something up.

I did get the cylinder to lock up late on those 2 teeth by peening but I was scared to go much further. If I had more experience with the process I'm sure it could have been done.

 

[Nick B]

Great info in this thread .

 

[jkmo]

I went to the armorers school and never heard of that. It was always a bigger hand until a new extractor was needed. Where did you learn this?

 

[Hondo44]

Thanks Hondo! I did try to peen the teeth but I made very little progress and I was worried I'd mess something up.

I did get the cylinder to lock up late on those 2 teeth by peening but I was scared to go much further. If I had more experience with the process I'm sure it could have been done.

Don't feel bad, it's always good to not get carried away and err on the side of being conservative. I'm sure just a little more aggressive peening would do it. Once one watches a S&W factory trained gun smith re-align a revolver yoke with a Babbitt hammer for example, like they do during manufacture, it's easier to apply the proper amount of force.

 

[Abflyboy]

My -3 had the same problem. Pretty sure when I got it that it was part of an estate liquidation and had never been shot.

I peened the 2 teeth on the extractor for the 2 affected chambers and it's been good for hundreds of rounds over the last 10 years. I figured it was a temporary fix and would need to be 'properly' repaired but it's still going strong.

 

[Hondo44]

While studying the problem on well worn revolvers I realized what the issue was and experimented with peening which was very successful.

My post #2 above:
When later researching the issue I was gratified to find the very same process described in Pat Sweeney's "Gunsmithing Pistols & Revolvers", 2nd Ed.(2004), pp.219-220.

While I'm aware that the factory usually recommends new parts replacement, and many gunsmiths have evolved into "parts changers", less expensive methods have been successfully used by true gunsmiths for many years.

 

[Hondo44]

My -3 had the same problem. Pretty sure when I got it that it was part of an estate liquidation and had never been shot.

I peened the 2 teeth on the extractor for the 2 affected chambers and it's been good for hundreds of rounds over the last 10 years. I figured it was a temporary fix and would need to be 'properly' repaired but it's still going strong.

Congrats.

I've never had to do the same gun twice. I believe the stainless guns are more susceptible to ratchet teeth 'deformation' because it's generally more 'elastic' then carbon steel, and much softer than the hand. It's not really wear, just needs the metal put back or 'upset' back to where it belongs.

I don't generally own stainless guns but have two. If they were my regular shooters I'd replace the SS extractor star with blue carbon steel like S&W nickel plated guns.

 

[MygunisaS&Wrevolver]

I've never done peening so I am not familiar with the method and can't comment on how good it is . I have used the following method that uses the oversize Power Custom hand along with dressing or equalizing the ratchet faces with a Barrette file. The Power custom hand are really oversize .103, but the instructions tell you to enlarge the left side of the frame window to fit the hand and then file a recess in the left side tip of the hand to fit the lowest ratchet and then equalize the other ratchets to this same point. By filing the recess in the tip of the hand, it gives you leeway for wear and allows you to fit another hand if the ratchets wear, you just make less of a recess.

 

[ken158]

I went to the armorers school and never heard of that. It was always a bigger hand until a new extractor was needed. Where did you learn this?

+1 on this and always check carry up with empty brass loaded in cylinder and cock back with very slight finger friction on side of cylinder. Don’t baby it because that is not how it is designed to operate. I see many guys here trying to fix something that is not broken...