S&W M-67 problem w/ cylinder stop

[SeanSw]

I was just dry firing my M67 with fired brass cases when the trigger and hammer locked up. I was able to open the cylinder and noticed that the protruding part of the slide stop will not go down entirely, thus locking up the system.

The revolver was returned to the factory less than a year ago for a tune up and has worked great since.

I am not experienced with gunsmithing and have never removed the sideplate from this gun, althoug looking at the slotted screws I can see that it has been done before. Does this sound like a problem that is easily solved at home without a gunsmiths tool bag?

*EDIT*

Large image ahead!

 

[Jim K]

First, if you do remove the side plate, make sure you release the tension on the mainspring (hammer spring) first.

I assume you mean that you pull back the cylinder release so the gun will cycle with the cylinder open, and found that the cylinder stop was not moving down as the trigger was pulled. That condition could be caused by several things, but dirt is one of them.

Before doing anything drastic, here is my suggestion:

Get a good penetrant spray. I recommend G96 Gun Treatment, but there are other good ones (not WD-40, which will gum up). Remove the grips and with the hammer cocked spray the penetrant into the gap in front of the hammer, and into the gap in front of the trigger. Soak the heck out of the gun, working it as you go.

Let it drain, then apply a few drops of good gun oil in the same places, and see what happens.

Jim

 

[SeanSw]

Hi Jim, when the cylinder is open I cannot press the cylinder stop down with any amount of force. It is down just far enough to close the cylinder, but its binds very tight. The action is entirely locked up and I cannot cock the hammer or pull the trigger. I can't cock the hammer to spray any penetrant inside

I will try releasing tension off the mainspring and removing the sideplates.

 

[SeanSw]

Alright, I managed to tap off the sideplate with the end of a screwdriver. No prying was needed, but it does shed some light on the slightly bent corner which has never laid flush. I'm guessing that a previous owner can be thanked for that.

I took a closeup of the internals and believe that I can see a problem. The three concentric circles are around a coil spring in the lower right corner of the trigger area. The spring looks bent and twisted in the middle, with one end behind the black piece of metal touching the trigger, and a few coils on the right pressing against the frame. Is this typical?

I have no experience in these matters and have yet to put it back together again. The cylinder and crane fell out, but I didn't do anything purposefully to loosen or remove them. Should this happen normally, or did I screw something up? I'm not afraid of tinkering but have no gunsmithing aspirations and am not equipped to tackle any problems. I only went this far because the screws were already banged up and I like to do exploratory observations on mechanical things.

 

[SeanSw]

I am cross posting this to the revolver forum to look for more advice.

 

[Jim K]

OK, pretty easy fix.

First, that spring sits between the frame and the cylinder stop. See if you can take a tool like a dentist's pick and pull the spring out of there. You may mess it up, but it looks pretty bad right now. A new spring may be needed.

Then pull the cylinder stop down out of the slot in the cylinder window and pull it out. You may have a bit of trouble getting it past the trigger, but it will come. Now you will see a hole in the front of the cylinder stop. That is where the spring should be seated. If the spring is still usable (not permanently bent) or you have a new spring, you can seat the back of the spring in the hole and push the cylinder stop back in place, pressing the front of the spring in so it goes into the frame. Make sure the spring is in position and not kinked. With the cylinder stop again in place, make sure it moves freely and is activated by the trigger before replacing the sideplate.

It looks like the person who had the gun apart before (not S&W, I'm sure) didn't get the spring seated right, so it probably sort of worked for a while, then got wedged in, stopping the works.

(Note that I would buy a new spring from Gun Parts Corp; you could probably find one that would do at the local hardware store, but the quality will not be as good and it might not last as long.)

Jim

 

[SeanSw]

Thanks for the advice Jim!

It looked like a job that could be done without harming my gun but Smith and Wesson offered (when asked) to send a call tag for my revolver. Their factory replaced the cylinder stop last year and they were the last people to have the sideplate off, and I'd like them to fix it. The spring turned out to be entirely broken and the piece fell out while poking around.

My S&W revolver shop manual also arrived today to inspire more confidence in disassembling the gun. Good sense told me to hold off awhile and hope that S&W will make things right in a timely manner.