Model 36 continuing problems

[opos]

I posted some time ago about a beautiful little 36 with a 3" barrel I bought a while back...it's the early flat latch with square butt..probably an easy 95% gun. I had issues when I bought it..the flat latch is very very difficult to operate to get a crisp release on the cylinder....Since the gun had been a safe queen for some time I took it to a good smith here and had him tear it all down, fully clean and lube it and double check for any defective parts or problems...he did so and said there is nothing at all that he can find to cause the really hard opening...His only comment was they are often hard to work in that early configuration and that I might consider replacing the flat latch with a newer rounded and higher latch...I could keep the flat latch for the time I might want to sell the gun

Is this a reasonable "fix"? I have had and do have a number of revolvers and aside from arthritis I usually get along fine...but this one is really tough..I have the original numbered grips that appear almost unused..

I'd appreciate any thoughts or comments please..many thanks

opos

 

[Old cop]

I have a flat latch Model 38 that has the same exact problem and I eventually stopped carrying it. If you plan to carry yours this "fix" sounds reasonable.

 

[steelslaver]

With the cylinder open does the latch move easily. With cylinder open it you should have to press it back, but it should slide easily. If not there is a burr on either the bolt mechanism inside the gun. or on the latch itself, or the spring and follower that move the bolt are buggered up. Also while open does the pin in lug on barrel move easily? If not that spring or that bolt is messed up. Possibly the cross pin is messed up, but, I doubt that. Again with cylinder open does the pin sticking out of the cylinder's extractor star press in and pop out easily? If not the check the internal pin for straight and smooth, also check for buggered springs. springs. Is the rod bend? the problem is likely in one of these areas. If the latch doesn't move easily one or more of these items is not right.

Oh, yea, the length of the ejector rod. It might possible be a touch long and bottoming out the bolt in barrel lug. Check how far the total movement on the bolt is with cylinder open. Then see if while closing if tight as the end of the rod moves into place if it binds because it trying to go farther than that.

 

[Bruce51]

Just a couple of thoughts on this issue. Is your extractor rod square on the end where it goes into the locking bolt?

Does the locking bolt move freely when you press on it?

A tight locking bolt, that piece that is on the barrel underlug, will make pressing the cylinder latch difficult.

If your extractor rod is out of square, loose or perhaps even a bit too long that will cause the problem that you are having.

Steelslayer is a faster typist.

Check it out and report.

BLM

 

[Alk8944]

"Is this a reasonable "fix"?" No, it is not! The style of the thumb piece has nothing to do with function!

Point 2, the two styles of thumb piece are not interchangeable. The "Bolt" is different. The "Flat Latch" style is retained by a screw into the bolt. The later thumb piece mounts on a stud that is integral to the bolt and is retained by a domed, slotted nut that looks like a screw.

If the extractor rod is tight the following instructions will fix probably 98% of the "Hard opening cylinder" problems. The rest can usually be "fixed" by cleaning the back of the extractor and its' recess in the cylinder.

The most likely thing is the extractor rod is slightly too long, or the center pin is too short! It is the relationship between these parts that keeps the "Locking Bolt", the plunger in the barrel lug, from being fully disengaged by the center pin. The center pin cannot be made longer, (readily), but the extractor rod can be shortened. Refer to the photo below. Open your cylinder so it is in the position in the photo, with the center pin being held forward by the breech face. The photo is a bit exaggerated, but it represents the proper relationship between the extractor rod and the center pin. The center pin should be flush to a bit above the end of the extractor rod. "Scratch" across the end of the end of the extractor rod with your fingernail. It should flow smoothly across the interface between the extractor rod and center pin without catching. If it catches on the rim of the rod the locking bolt does the same thing and this is what makes the gun hard to open! Shorten the extractor rod until you no longer catch your nail on the rod rim and the gun will now open easily. Disassembling the gun and chucking the extractor rod in a lathe and removing .005" to .010" from the front end will usually be enough. You can use a drill press and a piece of coarse abrasive paper or a single-cut flat file laying on the table and this will do just as well as the lathe. If you are careful and can hand file the end of the rod and keep it square a few strokes will do the job. Be careful, this needs very little metal to be removed to complete the job!

(This is a Model 12, note the color difference between the black anodized frame and the steel barrel, cylinder and yoke!)

If you are not aware, "mouse" over the thumbnail and it will enlarge greatly.

 

[steelslaver]

Great explanation on the fit up of these parts. This is probably the problem if the latch moves smoothly, but the cylinder doesn't release smoothly when latch is fully forward.

I have never seen it on a S&W, but have on a CA where when the cylinder is open the end of the extractor bolt isn't flush with face of the recoil shield. If this happened on a S&W it would not move the extractor center pin enough to release the cylinder properly on either end.

 

[wrangler5]

I have had two models with a "notchy" feel to the swinging out of the cylinder when the latch is pressed fully forward. In both cases the problem (as I diagnose it) is that the bolt (the part that pushes forward on the spring loaded locking pin in the middle of the extractor star when you push the cylinder release) can not move far enough to come fully flush with the recoil shield.

The locking pin in the center of the extractor star has a convex end, and if the bolt comes fully flush with the recoil shield this pin just slides smoothly off the bolt and onto the recoil shield as the cylinder swings out. But if the bolt is not fully flush with the recoil shield when you start to swing the cylinder out, the convex segment has to ride up over the tiny ridge made by the recoil shield around the not-quite-flush bolt. (If the locking pin were square on its end it would stay locked in its locking hole unless and until the bolt lifted it up flush - the convex end allows it to ride up and over the lip of the recoil shield hole, but it takes extra pressure on the side of the cylinder while opening it to make that happen.)

One of the guns with this problem was a brand new 432PD that I sent back to the factory for this and another problem. They determined the gun was unrepairable and would not be returned. They have no 32 caliber guns to offer as replacements, and we are in the midst of trying to find an acceptable (to me) substitute from their current production lineup. They have said they will NOT give me the money I paid for the gun.

The other "notchy" gun is a 2" M64, which works perfectly except for a slight hitch when first swinging the cylinder out. It is a no-lock gun whose innards have worked themselves into a glass-smooth symphony. There is no way I will ever let the factory get their hands on this one, after my 432 experience, as I'd be concerned they'll condemn it too and offer a new 4" 64 with a lock in its place. Sorry, but I prefer the notch. And sadly, this experience has caused a reexamination of my previously favorable view of the "lifetime warranty" people talk about. I suppose some gun is better than nothing if your gun truly breaks, but for anything less than a completely nonfunctional gun with no prospect for a fix other than by the factory, letting the factory get hold of a gun that you like runs the risk of being told they can't/won't fix it and you can only have something from the current product line to replace it. If what they make now doesn't fit your preference for caliber/finish/features, too bad.

I have not come up with a homebrew solution to the "short bolt" problem as I diagnose it. I've taken the 64 apart and there are no bits of crud limiting the bolt's forward travel, either on the frame near the bolt hole or in the frame slot where boss for the latch button travels. There might be a way to take a few thousandths off the front of the boss, to let it go a tiny bit farther forward, but the problem isn't bad enough that I've tried to explore that in detail.

 

[opos]

Wow...thank you all for the input..ok, there were a number of suggestions so I'm going to take them one at a time..

First, with the cylinder open the flat latch is forward and I can slide it to the rear smoothly and easily.

Second the small pin in the lug at the front of the barrel where the pin locks in when the cylinder is closed slides back and forth easily.."at rest" with the cylinder open there is a short amount of the little pin sticking out in front of the lug and a small amount sticking out at the rear of the lug....when the cylinder is closed there is just the little bit sticking out at the front of the lug.

Third as to the pin sticking through the extractor star..it's very hard to operate...I can push it with something like a metal coin but it's almost too hard to push in with my finger...The pictures shown are with that pin depressed into the star by pressing the pin against the edge of my desk with the cylinder open...this is the only way I can get the center pin to push all the way in...I'm older with arthritis but this is still way too hard to push in my opinion.

Fourth the little pin in the lug at the front of the barrel where the long pin hooks in does not seem to have any binding...as the cylinder and crane close the rod looks to have a couple of thousanths clearance as it snaps into the lug over the little pin..when it's closed and locked it still looks to have that tiny space so does not appear that the problem is with the rod binding on the little pin.

Fifth the end of the center rod that goes through the pin appears to be flat and not damaged at all.

Sixth...the pictures mostly apply to this...I mentioned I have to really push the pin that goes through the star to get it flush..really hard...The smith that did the "work" thought the pin might be bent but said it's not and thought the spring inside the pin might be bad but said it is fine....I can push the cylinder down on the edge of the desk (flat) and the pin goes flush with the teeth on the cylinder and that is what the pictures show....If I take a sharper "tool" like a phillips screw driver and push the pin I can push it a bit further and it will extend out of the rod just a few thousanths...I could not get a picture as I'm short a couple of hands to get that shot...the pin has to be forced "past" the "flush" area on the back of the cylinder to make it stick out of the rod.

One final thing..in fooling with it I do notice one thing I did not pay attention to before..If I sort of "wiggle the cylinder" as I'm trying to release the latch it seems to help just a little...still very tight but it seems to be a bit easier and more positive. Pushing the latch seems to sort of bind or drag as it tries to move forward..this has always been the case.........

That's what I've found...any thoughts much appreciated.

 

[opos]

Wondering if the recoil shield is a problem after the post above..took a couple of pictures...there is a definite wear track and also there might be the slightst "groove" as part of the wear pattern...wonder if this could be an issue that, along with the very tight and hard to depress rod might be a problem?

 

[wrangler5]

Here's what my M64's too-short bolt looks like. It's not very much short, but enough (I think) to cause the notchy cylinder opening.

BTW, in my experience the groove in the recoil shield is just normal wear. I surmise that in a brand new gun, the rounded tip of the locking pin contacts a very tiny section of the recoil shield as the cylinder opens and closes and focuses all the spring tension on that line, wearing a slight depression. As the line deepens/widens, the area contacted by the pin grows, so the pressure per square inch declines until the depth/width of the depression finally stabilizes.

 

[armorer951]

Did your gunsmith check for end shake on the cylinder and/or the yoke? Sometimes end shake can be a factor in the cylinder problem you describe.

 

[poordevil]

I have a model 66 that was always trouble free. I used and carried it a lot for many years. Then did not use it for awhile. The pin in the extractor star appeared to have gummed up grud in it as the cylinder latch became hard to push. I took cylinder out and put it in a baggie and sprayed it with that gun blaster gun cleaner and let it sit of a day or so. Works great now.

 

[Alk8944]

...any thoughts much appreciated.

opos,

Yes! Read my first post!

Your last photo, and to a degree the others, show that the center pin is not coming fully flush with the front of the extractor rod! You will feel the catching if it is only .001"-.002"
short of the center pin being flush! Read my sig. line, I am completely serious about that. I have been doing this a very long time and have fixed this same problem many times.

You didn't even try checking the fit as I described, did you?

The slightly below flush bolt will cause a slight catching, but because of the rounded it will not make opening difficult.

 

[opos]

Ok...I'll try and follow along. I may have gotten confused by wording. The "extractor rod" is the rod that goes from the crane to the little lug under the front of the barrel that has the pin (springloaded) that goes through it..it is that pin that engages the small pin in the lug under the front of the barrel to lock the pin, crane in place...correct?

The pictures I took show the pin going through the rod with the gun laid against my desk top so it will push flush with the star on the extractor...when pushed flush you end up with what I show in my pictures..the rod is about "even" with the end of the extractor rod. In your picture it shows that the pin inside the rod extends quite a distance beyond the front edge of the rod. Is this the area where my gun needs work..?

If I'm understanding you are saying that the end of the extractor rod needs to be shortened by a couple of thousanths of an inch and the tip of the pin inside the rod needs to be flat across after it's allowed to protrude that couple of thousanths.

If this is "on track" I can do that (have a buddy that is a top aerospace machinist with top tools). My question arises that the pin that goes through the ejector rod and also goes through the star on the back of the cylinder is extremely hard to press open by hand (pushing against the tip that extends out of the star with my thumb). Does this seem normal?

Now, assuming (hate that word) I'm understanding properly it appears I can remove the crane/cylinder assembley and carefully file (tiny bit at a time) the end of the extractor rod (at the front of the rod where it contacts the little lug under the barrel)..It would seem I could do this without removing the spring loaded pin from inside the rod...see my first picture of the assembley "at rest"...there is a significant amount of space between the opening at the end of the rod and the tip of the rod itself...If I can take a fine tooth flat ******* file and gently dress down the end of the rod until the pin shows some protrusion when pushed forward from the back (by the star) will this accomplish the repair? I can easilly block off the opening at the tip of the extractor rod so that no debris get's into the tube around the pin.

I was just a bit confused by your first picture as it showed a much shorter tube and pin configuration but I guess that might be a shorter barrel revolver and also a different model..Your first picture shows quite a protrusion of the pin through the tube...it this "at rest" or is it "extended"..as I've mentioned if I really put the pressure on the pin with a small diameter tool I can approximate the results in your first picture but it takes a tool to force the pin past the teeth of the star and some really extreme pressure (Example I can take a small phillips head screw driver..carefully place in on the rounded portion of the rod by the star and then very carefully push with a great deal of force on the screw driver..the rod with push through the tube and will extend several thousanths past the tip of the tube.
I think this is an "un natural situation because of the force required..there is enough physical space in the tube for the pin to make the full travel but it's very , very difficult to get the pressure on the rod to do that...I did have the smith look at the tube, the pin and the spring for condition and he indicated there were no burrs, the spring looked ok and the tube and pin were both straight.

Many thanks for taking the time with me...I am pretty good at mechanical things and don't fear fixing the problem with the proper understanding of what's needed and I understand what you say now....

Am I on the right track now?

Many thanks,

By the way do you know a Man named Don Crosgrove in Sandy? I think he grew up there and may sill live there..be a guy in his late 60's or possibly 70..he lived in Heber City for a period but pretty sure he came back to Sandy...


This is all sort of describing a spiral staircase without using your hands.

 

[opos]

I think I may be on the track..here are a couple of pictures I was able to take that shows the pin inside the extractor tube..these were taken with the cylinder barely cracked open so the breech is forcing the pin forward in the tube...This is just as the assembley is about to "lock up" with the pin in the lug on the barrel. It looks like the pin is flush with the lip of the tube where it locks into the lug..if this is so and from the discussion before...the pin should have a few thousanths protrusion at this phase of the cycle...correct? If that's it I have no doubt that I can pull the crane and cylinder out of the gun and very gently dress down the edges of the tube a few thousanths of an inch shorter to get a tiny amount of protrusion of the pin....

Am I on track??
Thansk

 

[iPac]

I have a feeling that the "stiff" center pin is the problem. The OP states it is clearly difficult to depress it and it is almost not possible by finger pressure. That would account for the difficulty opening. Need to lighten it up somehow.

 

[opos]

I have a feeling that the "stiff" center pin is the problem. The OP states it is clearly difficult to depress it and it is almost not possible by finger pressure. That would account for the difficulty opening. Need to lighten it up somehow.

I had thought that as well and as soon as I see if I'm on the right track with a minor shortning of the extractor tube I might pull the pin out and give it a good polishing with something like mag wheel polish or something to just "slick it up" a bit...figured to take one step at a time....I also have some very fine crocus cloth that would make sure the pin is not dragging...but again, waiting to hear if the pin shortening looks like the next step...thanks again

opos

 

[BE Mike]

Kroil works wonders on penetrating and freeing up gummed up actions and parts.

 

[opos]

Thanks...I'd already given it a good soak in Kroil..I restore antique engines and buy Kroil by the gallon...great stuff...

 

[opos]

Neighbor shortened the rod (good machinist) to the level where there was no "lip"...made no difference...he felt there may be a burr of some sort inside but was short on t ime...It's going to Smith if they will take it to fix and if not going to consignment at the LGS...like the little gun but not married to it...something is wrong and what I've tried has made no difference..thanks for any comments.