Fixing up a .32-20

[Truckman]

^^^^^^^^^^^
The longer I am a member here, the more amazed I become concerning the amount of knowledge I was not aware of before...I continue to sit and absorb......Ben

 

[OrlontheBrave]

There are three other tests you might do. First, make sure the hammer, trigger, and rebound slide studs are tight. If any are loose, they can cause a stiff hammer and/or trigger when the side-plate is on and tightened up.

Second, make sure that when the gun is assembled, there is no drag coming from the extractor rod. Hold the gun in your left hand, and very slowly, pull the hammer back, just until the cylinder stop unlocks the cylinder. The cylinder will now turn free, using the thumb of your right hand. Slowly rotate the cylinder counter-clockwise. If it feels tighter in one or more positions, and then easier in other positions, the extractor rod and or the yoke is bent. Try spinning the cylinder by using that thumb to push up quickly on the side of the cylinder. It should spin freely about 1 rotation.

Brownell's makes a simple yoke alignment tool, that will test for yoke alignment. A slightly bent yoke will cause lots of drag.

A last test is to single-action the gun through all 6 chambers. At each charge hole, push the bolt forward, to disengage the front extractor rod locking pin. Note the position of the muzzle-end of the pin, when the bolt is released. Does the end of the pin return to the same position, for each charge hole, or does it stick out too far on one or more charge holes?

Regards, Mike Priwer

Thanks Mike! The gun passes the second two tests. I haven't tried the first yet, but will again when I disassemble the revolver.



I picked up a Lyman trigger pull gauge today: single action is 7, 7.5 lbs, double action is well over 12 lbs. I polished the cylinder stop and cylinder stop area of the frame, but that doesn't seem to have helped much. Back in I go.


Edit: studs seem pretty tight.

 

[OrlontheBrave]

Just to see what would happen, I installed the Wolff mainspring and 15lb rebound spring. Single action breaks at 8lbs? double action is 11-12lbs, and the trigger gets stuck on return midway, the same point it slowed down with the stock springs.

 

[mikepriwer]

There is yet another approach to testing, that might be of help.

For locating problems in the lockwork, first remove the cylinder and yoke from the gun.
Now we do a series of tests, with the sideplate in place and screws tightened down.

1. Remove everything from the lockwork, except the studs.

2. Put in only the hammer, replace the sideplate, and tighten it down. All 4 sideplate screws should be used. Flip the hammer back and forth. It should move with complete freedom. This will test the hammer stud for tightness.

2A. Repeat step 2, with the addition of the bolt, complete with its thumbpiece.

3. Remove the sideplate, add the mainspring, tighten it up, and replace the sideplate and tighten down the screws. When pulled back and released, it should fly forward with complete freedom. Pull it back again, and let it come forward slowly, by using your thumb. See if you can feel any binding.

4. Remove the sideplate, and the hammer and mainspring. Put in only the trigger, without the hand. Replace and tighten the sideplate. Flip the trigger back and forth. It should fly freely from one end of its travel to the other. This will test the tightness of the trigger stud.

5. Repeat step 4 with the hand added to the trigger.

6. Repeat step 5, with the rebound slide and its spring added. Now you can squeeze the trigger and release it slowly. Does it return completely to its forward position? Test the trigger pull now, and for each succeeding step with the trigger and rebound slide in place. Note what, if anything, happens to the trigger pull, as lockwork parts are added back.

7. Repeat step 6 with the cylinder stop added.

8. Repeat step 7 with the hammer and main spring added. Tighten the main spring screw all the way, replace sideplate and tighten all 4 screws. Test the lockwork in single and double action. Also test the trigger pull.

If, at any step along the way, the problem symptoms return, back up one step, repeat it to make sure the problem went away, Then come forward one step and repeat it. The problem should reoccur.

If you have not yet identified the problem, then you want to slowly add the cylinder. With all the lockwork installed, you can now test the cylinder, part by part. First, remove the extractor lug locking crosspin, and pull out the extractor lug locking pin.
I can suggest the steps, if you need to do this.

Regards, Mike Priwer

 

[OrlontheBrave]

There is yet another approach to testing, that might be of help.

Thanks Mike! My approach so far has been similar but far less systematic, which might explain why it hasn’t worked so far . . .

2) Hammer moves freely, perhaps too freely: there’s some side to side wobble and a visible gap.

2a) Hammer still moves freely, and adding the bolt reduces the wobble/gap.

3) Passes with aplomb.

4) Trigger moves freely. Some wobble, but less than the hammer has.

5) Hmmm that’s interesting. The hand doesn’t seem to want to move. I removed the hand and put the sideplate back on and the trigger moves smoothly. Next I removed the hammer block plunger from the sideplate and reinstalled it, and the trigger and hand moved smoothly. With the hammer block plunger back in the trigger/hand are sticky. I think we found a/the issue! I never would’ve discovered it on my own.

Now the next big question: how the heck do you clean/polish the smallest, least accessible hole on the gun?

 

[mikepriwer]

I don't know which hole you are referring to, but you might try a thin pipe-cleaner.

By the way, how is that plunger and spring retained in the side plate?

 

[Muley Gil]

Thanks Mike! My approach so far has been similar but far less systematic, which might explain why it hasn’t worked so far . . .

2) Hammer moves freely, perhaps too freely: there’s some side to side wobble and a visible gap.

2a) Hammer still moves freely, and adding the bolt reduces the wobble/gap.

3) Passes with aplomb.

4) Trigger moves freely. Some wobble, but less than the hammer has.

5) Hmmm that’s interesting. The hand doesn’t seem to want to move. I removed the hand and put the sideplate back on and the trigger moves smoothly. Next I removed the hammer block plunger from the sideplate and reinstalled it, and the trigger and hand moved smoothly. With the hammer block plunger back in the trigger/hand are sticky. I think we found a/the issue! I never would’ve discovered it on my own.

Now the next big question: how the heck do you clean/polish the smallest, least accessible hole on the gun?

Using number drill bits, TWISTING THEM BETWEEN YOUR FINGERS, NOT IN A DRILL!!!!!!!!!!!!!!!!!!!, you can clean the hole. Finish using pipe cleaners dipped in solvent.

 

[OrlontheBrave]

I don’t have any number drill bits, so I’ll try pipe cleaners for now and see if that helps.

The plunger has a slot cut into it. The hammer block (the springy arm thing attached to the sideplate) presses up on the plunger, locking it in place. Due to the slanted cut in the plunger, when it’s pressed in the arm retracts.

Unfortunately the hammer block and that little plunger spring are always pressing on the plunger, so it’s always rubbing against something as it’s pushed in.

 

[Truckman]

A pin vise might be useful......Ben

 

[OrlontheBrave]

A Lord not another tool I need!



Reassembled, unfortunately the trigger pull weights remain the same, and the trigger still sticks on rebound. While the hammer block and plunger was "a" problem, I guess it wasn't "the" problem.



However, I did notice that with the cylinder out (and the cylinder release drawn to the rear), when dryfired the rebound no longer sticks. I verified this by removing the cylinder assembly and dryfiring again.



I'm starting to think the rebound issue may be cylinder related, while the heavy trigger pull might be caused by something else.


Edit: I think I figured out the source of the binding on rebound. It only occurs with both the cylinder stop and hand in place, and only when the cylinder is in the gun. I think as the hand drops and retracts it drags against the extractor star pushing it down ever so slightly. Meanwhile, the cylinder stop is finishing the last of its forward travel, which is impeded by the additional pressure from the hand. Ergo, it binds. I do not know, however, how to fix this. I tried polishing the leading end of the cylinder stop and the bottom part of the hand, however that hasn't fully fixed it yet.


Edit: Edit: That would also explain why the issue doesn't arise when the sideplate is off or the hammer block plunger is removed: the hammer block plunger is the part that pushes the hand forward towards the cylinder.


Edit: Edit: Edit: The rebound issue is of course resolved when I replace the 15lb Wolff rebound spring I've been using for testing with the factory rebound spring. Unfortunately even with the Wolff mainspring this leads to a DA pull of 11.5lbs and a SA pull of 9lbs. I had been using the Wolff springs because, with the stock springs, the pulls exceeded the limits of my Lyman trigger pull gauge. For the time being I'll leave the stock rebound spring and Wolff mainspring in, as I puzzle out why the DA is acceptable and the SA is incredibly heavy.

 

[mikepriwer]

If I understand this correctly, there is still some binding, without the cylinder, but with the hand installed, along with the side plate, of course. This needs to be resolved, first.

With the side plate off, does it's plunger push in and out freely when holding the leaf spring down so that it is not rubbing on the plunger?

If so, do you have a micrometer or calipers? If so, measure the OD of the plunger, and then I can translate that to the proper drill size. Then you can get the proper drill bit, and as Gil suggests, twist it with your fingers, and get the plunger hole completely cleaned out.

If the plunger is not sticky with the leaf spring depressed, maybe the ramp on the plunger is rough, and needs polishing. That plunger of yours looks like it has circular ridges going around it's perimeter. That should be a smooth surface, so maybe those ridges are getting hung up on the edge of the leaf spring.

Mike Priwer

 

[glowe]

The plunger appears to have been hand made from a screw shank?? It has a spiral thread root and a rough ground section that inserts into the spring, something the factory would have never done. Does it wobble in the hole? I cannot imagine it is responsible for such a high trigger pull weight, but does appear not to be a factory part. I checked Numrich and found that they do not have that part, but only sell entire sideplates complete. Never tried this, but if there is a way to defeat the hammer block safety, I would leave out the plunger and spring, assemble the gun and try the action. BTW, that emery cloth looks way to coarse to do any polishing??

 

[OrlontheBrave]

Hi Mike, the plunger moves in-and-out smoothly when I hold the spring down, so I think the plunger is either rubbing on the hammer block, or the additional pressure from the hammer block is causing it to rub on the plunger hole. I took a little 1000 grit and 2000 grit sandpaper to it yesterday to try to get those circular ridges off and while it's smoother, I wouldn't call it 'smooth.' I'll try again later today and try to get it smoother.

Unfortunately I'm not sure if the drill bit will work: on closer inspection I found that even with the hammer block arm pulled all the way down, it still blocks the bottom quarter or so of the hole. I was able to get a slightly undersized toothpick in there to clean some gunk out, but I'm not sure if I'll be able to get anything bigger, or if the hammer block is removable from the sideplate.

Hi Gary, the circular ridges don't look spiraled to me. I think the ridges are just an artifact of the machinery available in 1926 or thereabouts. I'd been looking for the part online as well, but can't even find a picture of it! Around 1930 or so they switched to a different style of hammer block and plunger, so I'm not sure how long this style was in production.

I tried the action with the plunger removed and the trigger and hand moved smoothly. Unfortunately, however, that plunger is the only thing applying forward pressure to the hand, so the gun won't function without it present.


I'm going to keep playing around with it, although now that I've given up on testing the aftermarket rebound springs I'm going to try and work to identify why the SA pull is so heavy. I'll try Mike's systematic strategy, first measuring the SA pull with only the trigger, hammer and mainspring in, then gradually adding parts.

 

[glowe]

Here is what I know, the quality of manufacture was much higher in 1926 then it is today and can guarantee that plunger did not look like that when it left the factory. I suppose it could have been butchered by an owner along the line, but not at the factory. You do not need the hand to cock and pull the trigger. You should be able to cycle the revolver and even use your trigger pull gauge without the plunger. Give it a try. Without the hand, you have eliminated two possible issues, the hammer block safety and the cylinder.

I added a close-up of the plunger.

 

[mikepriwer]

Here is a picture of the plunger in it's sideplate. Notice that it's surface is smooth - very smooth.

I wonder if your sideplate is original to the gun. You can see a number on this sideplate, placed in the milled-out region. That numbr should match either the serial number, or the work-order number. That number is found in the yoke area of the frame, and typically it's found on both the yoke and the frame.

I'm busy for a few hours today, but if I have time, I'll see if I have an extra sideplate with that plunger.

I, like Gary, believe that either your pliunger is a home-made replacement, or has been butchered by someone.

Regards, Mike

 

[OrlontheBrave]

Hi Gary,

I'm not sure this is the best example of old world craftsmanship: I had to remove two large burs, one from the rear of the window and one from the rear of the cylinder stop plunger hole. I'm not sure if they affected function, but they were big enough to cut my fingers.

Here's what the bolt looks like as well, even after a round of polishing: it has similarly deep scratches. Either the S&W quality control guy was asleep that day, or someone in the intervening 100 years took all the inside parts and chucked them in a blender.

I've started testing the SA as well (without the hand etc.). With just the hammer, trigger and Wolff mainspring in place it measured under 1lb. With the stock rebound spring and housing in, it went up to the 8lbs I've been seeing throughout testing. I'm going to inspect the rebound spring and housing next.


Hi Mike,

I checked the sideplate number against the assembly number and they match, so that part at least is original.

I wonder who opens a S&W revolver, takes the parts out, and makes them rougher instead of smoother.

Edit: Found some pictures of sideplates with plungers on ebay. They do look less chewed up.

 

[OrlontheBrave]

With the Wolff 15lb rebound spring and the Wolff mainspring, along with the bare necessities (hammer, trigger, rebound housing), the DA pull drops from ~12lbs to ~8lbs, however the SA pull drops only from ~8lbs to ~6.5lbs. With Wolff reduced power springs and minimal parts I would expect the SA pull to be much lower than ~6.5lbs (and even with the stock rebound spring I would expect it to be under 8lbs).



So I think we just have a few issues:
1) The much-discussed gritty hammer block plunger, which makes the trigger pull rougher and heavier than it need be.

2) The issue I found last night, where the trigger rebound hangs up midway, likely due to some sort of engagement/orthogonal pressures between the cylinder stop, hand, and cylinder. This issue can be overcome by using the heavier stock rebound spring in place of the Wolff rebound spring.

3) The heavy SA pull, which seems to be rebound spring/rebound housing related? Or spring related:
With Wolff mainspring, no rebound spring: <1lb SA
With stock springs and minimum parts: 6lb SA, >12lb DA
With stock rebound, Wolff mainspring: 8lb SA, ~12lb DA
With Wolff mainspring and 15lb rebound: 6.5lb SA, ~8lb DA

 

[OrlontheBrave]

I think I’ve fixed issue 1. I spent the majority of a boring Zoom meeting working the plunger back and forth using a pin punch, first with Flitz and then with gun oil. After that I polished up the slot the hand rides in. Here’s a not great photo, but hopefully you can see how the plunger no longer looks quite so rough.

Here’s why I had to work on the sideplate slot.

Look at those tool marks!

I also took the time to polish the left side of the knob on the rebound housing which I found to be rubbing inside the trigger.

With the Wolff mainspring and 15lb rebound spring in (as well as the hand), SA came out to 7.5lbs and DA to 9.5lbs. That’s only about 1lb more than the measurements taken without the hand in place.

Now on to problems 2 and 3! If I can fix issue 3 and get the SA trigger pull to a reasonable weight, I’ll likely just stick with stock springs and call it a day for now.

 

[OrlontheBrave]

I’ve been trying to figure out why SA was heavier with the reduced power Wolff mainspring than it was with the stock mainspring. A peak inside the frame reveals a possible culprit. Stock mainspring:

Wolff mainspring:

The Wolff mainspring is touching the rebound housing. Chamferring and polishing that back edge of the rebound housing dropped the SA pull from 7.5lbs to 7lbs.
Unsure what else to do: all the other parts are the same. I could try polishing or sanding the mainspring, or I could see if I can change the bend to be more like the old mainspring.

 

[OrlontheBrave]

Last night, looking through some old forum posts, I discovered 2 things: 1) Wolff mainsprings require a longer strain screw lest they touch the rebound housing, and 2) Smith & Wesson changed the dimensions of their strain screws around 1950 or so from 0.150” to 0.160”, so the spare strain screw I have doesn’t fit. The other dimensions are otherwise identical, so in what might have been a stupid move I chucked the spare strain screw in my electric drill and turned the threads down to 0.150”. I also ordered a thread restorer file to sharpen the threads, and that should get here next week. We’ll see if the modified screw works. I also tried sticking a spent primer on the end of the old screw, but I don’t think it added enough length.

I haven’t accomplished much today: I further polished the rebound housing (and frame), cylinder stop (and frame), and the little indent in the front of the rebound housing (and associated trigger arm). The bug screw I ordered also arrived and it fits fine so now I have all the necessary bits.

With the cylinder stop now inserted, the SA pull is ~7lbs and the DA pull is ~9.5lbs. DA feels a hair creakier, but it’s a good sign that adding the cylinder stop didn’t increase trigger pull weight. If there is roughness in front of the cylinder stop pin there’s not a lot I can do: my toothpick won’t even fit in there. It’s still missing the bolt and cylinder, and I think the cylinder will add some more weight to the DA pull.

While I wait for the thread restorer file I’ll fit the new stocks and keep hunting out rough parts and polishing them out.