S&W Hand Replacement


February 10, 2003, 05:43 AM
Believe it or not, I've never had the side plate off a S&W.

I need to replace the hand on an N-Frame (M29 44mag). Is this difficult? How far does the revolver need to be disassembled to get at this? Am I going to need any special tools? I feel like such a neophyte. :) I've done work on many other guns over the years so it should be doable.

Problem is that the cylinder isn't indexing far enough to lock when cocking the hammer (unless done forcefully).

Thanks for any suggestions.

If you enjoyed reading about "S&W Hand Replacement" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
February 10, 2003, 09:03 AM
You can do it. But unless you have a burning need to DIY, I'd just take it to a good gunsmith. Here's why:

You can buy Jerry Kuhnhausen's Shop Manual on S&W revolvers. It tells how to fit & replace the hand. Around $18-$19 bucks, plus shipping.

You need some tools. Hollow ground screwdrivers, stone, etc. By the time you do this, you will have more than $50-$75 bucks in tools, easily. (Granted, they come in handy, and you should have the screwdrivers anyway, but I'll explain further).

You need to buy a new hand, of course. Not expensive. Don't have a price list up, but oversize hands are available lots of places for (I'm swagging this) less than $15.

So you have a low end cost of $100-$125, depending.

How good a machinist are you? This is all manual work, and requires some patience. Also, it's not the job I would pick to learn these skills if you don't have them already.

The kicker is, it may not be the hand itself. (I don't know, you may be right, I'm not questioning your troubleshooting, just throwing out ideas, and I'm not a gunsmith, either). It could be that you have extractor problems, a worn cyl. stop, or some other problems. Could be just a weak handspring. If you need a new extractor, thats $27-30 plus shipping, btw.

What it all boils down to, is this. A gunsmith already has the parts, or can get them cheaper than you. He/she already has the tools, and if you pick a good one, won't have to fix whatever the problem is more than once.

I like to do things myself too. And I'm capable of doing manual work like this. I've got the tools, the book, and parts sources. But I won't. Because gunsmiths go to school, do apprenticeships, and do this type stuff alot. And the cost, in the end, is cheaper to just let one of them do it.

This is just my opinion. You may feel differently, and really want to get deeper into this, and that's fine. I'd buy two oversize hands, in that case. If you fix it the first time, you have a spare. If you make a mistake, you already have another to do right. It's like buying spring replacements. Why buy just one? (Granted, springs are generally less expensive).

Start with Kuhnhausen's book. Then you'll know whats required (if you haven't done this already). Hope any of this helps.


February 10, 2003, 02:26 PM
It could be that wear on the star is also contributing to the problem. If it "slips" on the same "tubes" each time around, suspect the star and eyeball for wear.

Could be wear in the frame slot is allowing the hand to be too far right so it is slipping past the star too early.

Oversized hands generally need to be fitted, A stock width hand may not fix the problem.

To change the hand, you have to strip the gun all the way down to the frame (except leave the cyl stop latch in) to get the trigger assy out. Takes some getting used to, but it is doable.

In addition to SW screwdrivers, get the brownells tool for replacing the rebound slide spring.

February 10, 2003, 08:32 PM
I attended the S&W Armorer's course a few years back. We were taught to install an oversize hand( oversize in thickness). There was no fitting to the hand; the fitting was to the ratchets. Some may take no filing; others varying amounts. Since then I have only had to fit one hand to a M29 for failing to carry up on 2 chambers. Those 2 took no filing of their respective ratchet but the other 4 did. Hope this helps.

Jim K
February 10, 2003, 11:18 PM
Caution: Working on an S&W ratchet is like the old joke about the guy trying to correct the wobble in a kitchen table by cutting on the legs. He ends up with a coffee table.


February 11, 2003, 10:14 AM
Thanks everyone for taking the time to comment. This is all very useful info. I've definately learned some things. My first S&W was bought 30 years ago. They sure built them for keeps in those days. This M29 came in it's present condition.

Don't mind my trouble shooting being questioned on this, like I said, never had to adjust a S&W before. How good a machinst am I? Welllllll, my degrees are in Robotics/Automated Systems and Manufacturing Technology. But I make all my $$ with computers these days. Closest I get to machining anything is modifying motorsickles, and handloading :). I'm pretty successful with handtools, files, stones and such but I don't own any decent machine tools. The last of 3 kids moves out soon!!! Then I can own tools without having to constantly replace and repair them.

The cylinder stop was something I had not previously considered as it was holding well. I don't have another S&W to compare it to. In comparison to my Super Redhawk the M29 does have a very light spring force holding it up. The stop on the M29 is not well rounded on the top, it has been attacked with a medium sized mill file file showing one heck of a large flat and several smaller flats. The stop's sides on the M29 are flat all the way to the top yet the Ruger's are beveled off near the top. A bit of beveling there could help it snick in, but that looks to be fostering a slight bur on the stainless Ruger. Looks like an unacceptable shortcut to me.

Upon magnified examination I note the ratchet's flats are flat and the corners all square. No evidence of wear. Putting a file to that is not in my game plan! I thought the fitting would be done by trimming the oversized length of the hand. Suppose I could peen it a bit longer since a new one is oversized in width? Learn something every day :).

All 6 chambers fall short by an equal amount. It's quite large by machinist's standards. A full millimeter of rotation to click in. There is no side to side play of the current hand in any position. It just doesn't lift high enough? Looks like I could bend the tip of the current hand up a hair to resolve the situation? The tip of the hand is lightly rounded, no sharp corners.

I think I got some good advice about taking it to a professional. Gonna think on it some more, might just end up taking the easy way out and dropping it off at Gutridge.

Thanks again!

February 11, 2003, 05:50 PM
Some gunsmiths have been known to bend the hand a bit to fit it. Be advised, it's a hardened piece so it has to be heated to bend and then re-hardened after.

4v50 Gary
February 11, 2003, 06:32 PM
Look for instructions in this forum under my name. There's a link that tell you how to disassemble your revolver.

Revolver Armorer
February 11, 2003, 09:04 PM
Forget replacing the hand with a wider part. The revolver will have irregular hard spots. Get a S&W qualified person to fix the gun. The ratchet pads will probably have to be re-equalized.

Revolver Armorer
February 11, 2003, 09:07 PM
The "Gunsmiths" that heat and bend hands need to go back to school. I suggest S&W factory school. :D

February 11, 2003, 10:13 PM
Revolver Armorer,
How do you get the cylinder to carry up if you don't replace the hand. I did go to S&W factory school and they taught us to replace the hand. We were told to measure thickness of hand before calling and they would send a thicker hand. True the chambers that were carrying up before would now be hard and their respective ratchets would have to be filed. I assume that is what you mean by re-equalizing the ratchet pads.

Revolver Armorer
February 12, 2003, 07:00 AM
Remember what happens when you put in a Hand cold with a new Ratchet assembly? The ratchet attempts to index, only to sit down like the fat women who cannot get up. A wider hand means invariably re-fitting some of the rachets surfaces. So I gather you know what I am talking about. Guys that bend, heat and among other things, aren't properly trained. Good school isn't it? :)

February 12, 2003, 06:40 PM
"The "Gunsmiths" that heat and bend hands need to go back to school. I suggest S&W factory school. "

You'll notice I didn't say I recommended it, just that some gunsmiths will do it.

Revolver Armorer
February 12, 2003, 06:47 PM
And that is the wrong procedure for DCU failures.

February 23, 2003, 12:54 AM
...yeah, I guess Jim Stroh, past American Pistolsmiths' Guild "Pistolsmith of the Year" and Nelson Ford, "THE Gunsmith", both need to go back to school, since they'll re-time an S&W revo this way...RIGHT!!!....mikey357

Revolver Armorer
February 23, 2003, 08:46 AM
The original poster (Ryder) asked about tools and how to complete the job. He sure doesn't sound like the candidate that should be self training himself in hand replacement (which does involve re-equalization of the ratchet surface. Stating that he's never had the slideplate off his M-29 or replaced the hand, wow. You sure are right, Jim Stroh he is not. Factory people do something that Jim Stroh does not do. They assemble, build and repair thousands of firearms every year. I look at these publications. "Diassembly of Firearms, Volume 1" and so forth. What is most funny is the fact that even mass sold "gunsmithing" publications don't even tell someone how to diassemble the cylinder correctly. :D
I would be jealous if I couldn't attend the factory school either. Funny how pro-gunners lose so much ground every year. I see their mannerisms and temprament on these boards all the time. They even bash people that learned from folks who build guns. Go figure? :D
Now go forth and mock. Tell me Mikey. What are the signs of a ratchet that needs equilization? How do you complete the process? Replace the hand with a wider unit? That's it? :confused:

February 23, 2003, 11:38 AM
AAHH, Grasshoppah, I was merely trying to point out that there's (ALMOST) always more than one way to skin a cat...and that, depending on the tools available, parts available, individual's skill level, etc., that what one "Smith" may be able to successfully execute shouldn't necessarily be condemned as "Not the CORRECT WAY" just because it's not what the factory teaches...get it???...mikey357, standing down, allowing RA to have the LAST WORD, which he so desperately wants....

Jim K
February 23, 2003, 02:56 PM
Ryder, I think you have a misunderstanding about how the S&W works. The hand does not push on the ratchet and then continue to engage it after the cylinder locks. The hand puts the cylinder in motion and then slips up past the ratchet as the cylinder stop engages. This works well, but takes fine fitting. Wear on the hand usually is on the side and a new or wider hand might help. But note that the S&W cylinder will almost never lock up tight with no movement at all. It is not designed to. S&W believes that if the barrel-cylinder alignment is close enough, the bullet will self align coming out of the cylinder and into the barrel throat. It seems to work. The slight amount of movement in an S&W cylinder is normal and will not be stopped by pulling the trigger, since the hand is past the ratchet and cannot force it around any more.

The old Colts, on the other hand, had a two notch hand. The first started cylinder rotation and the second engaged the ratchet when the trigger was pulled and forced it against the cylinder stop. The Colt system seems better as the cylinder feels "locked up" with no movement, but in fact it can force the cylinder OUT of alignment with the barrel if there is a lot of wear on the cylinder stop or cylinder notches.


Revolver Armorer
February 23, 2003, 08:16 PM
That is correct Jim. The Hand in a S&W is width sensitive unlike a Colt DA or SA which operation is height sensitive. Actually, barrel cylinder centerline is gauged two ways. "Service Grade" which is your basic safety gauging used by factory on final inspection. This is the centerline agreement that must be present to prevent high pressure curves on the forcing cone during "Forcement" (forward transition of the bullets bearing surface into the forcing cone). Take precision gauging a step further, a "Match Grade" Plug Gauge is used. Match Grade Plug Gauging is an exceptional test of Cylinder Mouth/Forcing Cone centerline agreement. This take handfitting and patients. I've had as standard S&W M-10 gauge out at Match Plug Gauge standards and drop the Match Plug down all six cylinders held horizontally. This can be done with real carefull fitting of the Cylinder Stop. (Althought I've seen them gauged vertically during assembly). The Cylinder Stop is the most important aspect of Cylinder alignment and overall feel. Now that Colt, wow. That's an interplay between the "Lifter", Rebound Levers cams, not to mention tension exerted on the Lifters Cam. The Actuator and Rebound relationships have to be very fine tuned. The Colt has barely any noticable cylinder side play. You almost never can drop a new Wider hand without re-equalization of Ratchet surfaces. Sure, anyone can tinker with a wheel gun. But it sure helps to have gun builders show you the right and proper way. :)

If you enjoyed reading about "S&W Hand Replacement" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!