Im going to attempt to fit an oversized hand into a k frame revolver that i have that seems to be out of time. Any suggestions or tips on where to stone the hand to make it fit or any other help would greatly be appreciated. Thanks!

You may need to look up the number of a local gunsmith, just in case. Certainly these are not drop in parts or are easily fitted unless you really know what you are doing.

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Dick

probably correct but i think id like to give it a try. any suggestions

Sorry, I would never try it myself unless I just didn't care what happened to the new hand.

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Dick

If it's an old K-frame - with some mileage - look at the cylinder notches and cylinder stop for leading/trailing edge wear. It may need a lot more than a pawl. Is there play in the cylinder rotation when you, after ensuring it is empty, pull the trigger and hold it back? Check those notches! Good luck.

Stainz

The hands are very hard and it would take a lot of stoning to get it fit to the gun. The correct way is to carefully file the hand window in the frame, and only file the side of the window on the left side looking at the window from the rear of the frame. By doing that, you get the hand closer to the extractor ratchets. Even if you do get the hand to fit in the window with no binding, you may still have to file the ratchets to get the correct carry-up, and that takes some knowledge to do so.. It would be best to have a gunsmith do the work.

As stated earlier, the cylinder stop should be checked first, and replaced before the hand.

Installing a new hand can be as easy as just replacing the old one with a new one, or it can take a lot of work! Like described earlier, you might have to open the hand window, and then you might have ratchet bind on some of them when some fit fine. Then you have to locate and carefully, correctly file the offending ratchet to just the right fit. I try to start by replacing the hand with one .002 larger to see if it corrects the deficient timing. You should not need to work on the hand unless you only have one that is so oversize that it binds the ratchets on cocking.

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Richard Gillespie
FBINA 102

Be VERY sure you understand what's going on before you remove ANY material from the frame!

Quite honestly, if you're asking how to do it here, I'd strongly agree that you have a pro do it.
Or, at the very least, invest in & study a Kuhnhausen manual before you start anything.
This is not something you jump into cold just because you want to try it.
Denis

SOME TIMES IT IS NOT THE HAND. IT COULD BE THE EXT.

Agree with Dpris. Get a Kuhnhausen manual and read it first. You won't regret getting the manual.

Agree with all the cautions listed above. If the symptoms are that the cylinder does not advance far enough (carry-up) to engage the cylinder bolt, all that's usually needed is to very gently and slightly peen the extractor ratchet notches associated with the offending chambers with a flat nose punch. This has the same affect as a longer hand (pawl) and will take several thousand more rounds before it misbehaves again.

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Jim
S&WCA #819

I like your thinking Hondo44. I have peened ratchets on some guns, rather than change the hands, and if you do it carefully, it definitely takes care of the problem. I have one .38-44 HD though that had one very chewed up ratchet (how & why I don't know, but I knew about it when I bought it) and another that was not much better, and tried oversize or thicker hands and peening, but neither worked, as the ratchet was so far gone. I ended up getting a brand new cylinder/ratchet in the wrap, from J&G in Arizona and fitted the cylinder/ratchet to my gun. The original cylinder would also accept .357 Mag rounds, which I checked after getting the gun home, and I was not too happy about it either, but for the price I paid and condition of the gun otherwise, I did okay.

I posted this before. This is a copy and paste for your pleasure.

Hand fitting does violate "file the cheapest part" rule. Before a wider hand will do any good, it must catch the ratchets closer to the center of the cylinder. This means you must file the hand's window only on the left side and only enough to allow the hand to move freely in the window. If you take metal off of the right side of the window or from the hand itself, you won't accomplish a thing, in fact you might make timing worse. In other words, you have to move the hand's point of contact to the left.
Installing a wide hand compensates for wear on the ratchets outer edge. The idea is to force the cylinder to turn a little farther and get a good lock-up. If the left tip of the hand is worn, it will not rotate the cylinder far enough. In this case, you can install a standard width hand to restore timing.
Hands are made of some hard stuff. It is a good idea to use some 400 grit sandpaper to break the sharp front edges of the hand so it won't bite into the window.
DCU or timing

DCU (doesn't carry up) or basic timing is easy to check.

How I check basic timing is pretty easy to do. Without touching the cylinder or holding back the cylinder just gently cock the hammer slowly in single action, (on all stations) and see if the cylinder stop snaps in place before the hammer falls. When the trigger is pulled to the rear (MIM triggers will rotate the cylinder further when the trigger is pulled) the cylinder stop must snap into the cylinder notch, if not, you have a problem.



One thing I must insist, before swapping the parts make sure it's not a loose fitting ejector causing your dry fire and poor carry up problems. This is true with non-pinned cylinders. Drop empty cases into the chambers then check your carry up. Sometimes the gun is fixed when cases are inserted in the chambers.



As the extractor ratchets, hand, and hand window wear, they get to a point where the hand won't rotate the cylinder far enough to allow the cylinder stop to snap in before the hammer drops (carry up condition in DA mode). This is not a hand length issue, it’s a hand width problem. If you take the side plate off and watch carefully in the hand window while pulling the trigger, you will see the hand cams off of the ratchets and the left side of the hand tip positions against the right section of the ratchets to rotate the cylinder those last few degrees.

Unless a gun has been fired a zillion times, the hand and the window seldom show wear, except for the left tip of the hand. Most times when you see a hand loose in the window, it's because it was shipped that way.
Factory hands run from about .093 to .095" and wide hands run about .098 to .100" There shouldn’t be more than .001 side play between the hand and window.

If the hand has worn thinner, or the hand window has worn wider, or the edges of the ratchets have worn thinner, you will start loosing carry up. Without fail, the ratchets are the most usual cause.

There are several solutions. The absolute best one is to replace the extractor (ratchets). Unfortunately, that’s a factory fitted part and you can't buy one without sending the gun back to the factory.

The next best option is to fit a wider hand. This will have nearly the same effect as a new extractor because it will take up the slack from ratchet wear and make the cylinder rotate a few more degrees. When the wider hand is fitted, you must widen the left edge of the hand window so the hand will be positioned a few thousands to the left.

An undesirable option is to lay a fine bead of weld on the right edge of the hand window then dress some material from the left edge of the window. This will position the hand closer to the ratchet and make the cylinder rotate further. Welding that thin of metal is sure to do some damage to the finish and could ruin the frame.

You can bend the tip of the hand slightly to the left. This will also cause the cylinder to rotate a bit father. The hand is made of some very hard material and will fracture if you try to bend it without first softening it. You have to heat the tip of the hand until it is red hot then let it cool to room temperature. It will then be soft enough to bend without breaking. Once you get the hand tip bent, you must re-harden the hand. Herein lies the problem. Most of us don't have the proper metallurgy skills to re-harden the hand. If it is soft, it will soon wear out.

One of the very precision specs in an S&W revolver is the hand-to-ratchet clearance. A few thousandths makes the difference between good and bad carry up. You want the hand tip to be touching the ratchet but not binding on it when the trigger is pulled. Basically a zero clearance.

If you insert the tip of the hand into the window, it should move freely with minimal side play. The tighter the better, as long as it doesn't bind.

The left side of the window creates a reference point in respect to the ratchets. You must move the reference point to the left before the wide hand will make the cylinder rotate more. That means you must take metal off of the left side of the window. Use a "safe" window file for this. Taking metal off the hand or the right side of the window moves the reference point the wrong way.

Once your wide hand is installed, the tip of the hand may bind on some of the ratchets. This will cause a bad gag in DA trigger pull. With the side plate off, watch through the hand window as you cycle the gun in DA. You win see where the hand cams off of the ratchet and the point of contact between the hand tip and each ratchet. Dress the ratchets at the point of contact so the hand is touching but not binding.

Go slowly changing the hand. It's easy to do and will fix your timing (DCU) problems.

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NRA Benefactor Member

Take care when attempting this. Striking too hard will shatter the lug and now you have a 5 shot...

Of course now your forced to send it back.

I done this myself so this should be your finale attempt before sending the gun back. Some extractors are possibly not available.

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NRA Benefactor Member

Yes sir, light hammer blows are the norm, and not with a 16 oz. hammer either.

should be required reading for any owner of a S&W Revolver. If you read it and understand it you will have learned what needs to be done and how or it will intimidate you and cause you to find a qualified gunsmith.

I have all Kunchhausen's manuals and refer to them constantly to refresh my memory for procedures that I do only infrequently. Patrick Sweeney's "Gunsmith: Pistols & Revolvers" (2nd Edition is out) is another excellent book covering S&W Revolvers.

One of the ways I judge a gunsmith is by looking at his library.

My father taught me two things that stand above all others:

1.Most things are easy after you've learned how.
2.There is no such thing as a stupid question, only stupid mistakes caused by NOT asking.

I have been smithing for 25yrs and we all started with our first repair or improvement.

Semper Fi

Here is a youtube how-to video by Larry Potterfield: YouTube - ‪Gunsmith - How to repair slow timed Smith & Wesson revolver‬‏

Which makes it look a bit too simple! Here is a discussion of the video, and some how-too:

How-to video on hand replacement--your opinion?

I had good luck with hand replacement (filing hand only, not the frame) on two N-frame revolvers, but the instructions with the Power Custom oversized hand (which I didn't strictly follow) suggested K frames might be a bit more tricky.

Hope it goes well for you.

sorry i took so long to reply. thanks for the advise and i fitted the oversized hand without too much of an issue. it corrected my timing problem nicely. i ordered 2 oversized hands, one to test my "skills" on and another one to install. going very slowly and with a fine stone it took me about 45 minutes to to it. now im sure my ratchets are worn seeing as how the revolver is 30 years old and has been shot alot.. but the oversized hand should work to solve the issue for another "few years" to come. thanks again for the insight

I know this is a very old thread, but, I wanted to ask a question on timing.

I know we always check for timing through single action. I have a friend whose 686 will fail the normal single action timing test, however, it will pass in double action with the same test.

If you put drag on the cylinder and slowly pull the trigger you can hear and feel the cylinder lock click twice and then the hammer falls just past that. Works every cylinder over several attempts even with more pressure on the cylinder.

In single action, it fails on all cylinders.

Seems really odd to me. The ratchets have some wear, I am no gunsmith, but it didn't look like the edges were worn significantly.

I check all my s&w revolvers in single and double action. I have also had occasion to fit an oversized hand in a high mileage 629. I got lucky. It was a perfect drop in fit and function.

A wee bit of hardface TIG welded onto the LH side and top of the hand has worked for me more than once. It takes diamond files, etc. to reshape the hand after welding, though! It's especially useful on the older models.

I lube the hand and the spur on the cylinder with moly. Since its a paste it stays were we put it. This will eliminate all wear and reduce friction. Don't let the hand and spur wear out.

Now the weld on the hand is harder than the spur on the cylinder.
Lube this area to prevent wear.

Have you been convinced yet that this is NOT a job for someone that needs to ask how? Unless your gun is a "donor" gun not intending to be used for anything but learning, I suggest you you contact a gunsmith who is experienced. When you have mastered quite a few other less complex fixes, you may want to get some video's to watch several times then try it.

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H Richard
SWCA1967 SWHF244