M64 Cylinder Stop Issues

[IamCaleb]

Hello guys/gals, I have an issue with my 64. After I bought it, I went to the range and put a 100rds through it with no issues. Two range trips ago I started to have "lockup" (for lack of a better term) issues. When the trigger was pulled, the cylinder stop would not release the cylinder to advance. You would have to gently pull the trigger exactly straight backwards for it to cycle properly. So, I took it home and detailed stripped it. Nothing stood out that said..."here is the issue". I ordered some Wolff springs (wanted to lighten the pull as well) including a new cylinder stop spring. Replaced all the springs and lubed everything up before assembly. Seemed to have cured the issue, till my last trip to the range. Same issue but, I noticed that if when pulling the trigger...if you pull slightly to the left...it locks up. If you pull exactly straight back, it works flawlessly. I noticed the trigger has a very slight wiggle room (left to right). Is this normal? Am I missing a spacer or washer that should be somewhere in there?

Looking for advice before it goes in to the Smith Shop or a reputable gunsmith.

 

[ken158]

Could be a weak cylinder stop spring and a lighter Wolfe spring replacement would do you no good. Take the cylinder stop out and clean everything good and replace with new factory spring. There are no washers or spacers in your gun (from the factory).

 

[shawn mccarver]

This is not normal. It is a serious issue as position of your finger on the trigger should not matter, nor should pulling the trigger "straight back" as you describe.

Because it is a failure issue that you don't want happening EVER, call S&W and send it back. Ask nicely for shipping label and include letter of instructions asking them to go through everything while they have it and bring it up to date as to parts, springs, etc., so it is like new.

 

[Stophel]

Long distance gunsmithing is tricky. Take the cylinder stop out, and see if you can cycle the action fine without it (with the cylinder removed, and you'll have to push and hold the thumbpiece back so that it will work). If you can't make it lock up with the cylinder stop not in place, then there is some issue with that part (or it's relationship to the trigger). If it still locks up, the issue is elsewhere, probably with the trigger. My preliminary bet is that the wobbly trigger is simply hanging inside somewhere when it is leaned on.

 

[Mike McLellan]

There are, however. shims that can be placed on either (preferably both) side of the trigger to eliminate side to side play. Another thing to check, since you describe the side play as minimal, is a bent trigger post. I doubt that that's the problem. It might be time for a trip to the Smithy.

 

[IamCaleb]

Could be a weak cylinder stop spring and a lighter Wolfe spring replacement would do you no good. Take the cylinder stop out and clean everything good and replace with new factory spring. There are no washers or spacers in your gun (from the factory).

This is what I did when I installed the Wolff springs. It was doing this before the new springs also. I installed a factory spec stop spring at this time. I do have a stronger spring for it from Wolff, maybe I can try this first.

This is not normal. It is a serious issue as position of your finger on the trigger should not matter, nor should pulling the trigger "straight back" as you describe.

Because it is a failure issue that you don't want happening EVER, call S&W and send it back. Ask nicely for shipping label and include letter of instructions asking them to go through everything while they have it and bring it up to date as to parts, springs, etc., so it is like new.

This is what I'm going to do if there is no easy fix.

Long distance gunsmithing is tricky. Take the cylinder stop out, and see if you can cycle the action fine without it (with the cylinder removed, and you'll have to push and hold the thumbpiece back so that it will work). If you can't make it lock up with the cylinder stop not in place, then there is some issue with that part (or it's relationship to the trigger). If it still locks up, the issue is elsewhere, probably with the trigger. My preliminary bet is that the wobbly trigger is simply hanging inside somewhere when it is leaned on.

It does not lock up with the stop out of it.

There are, however. shims that can be placed on either (preferably both) side of the trigger to eliminate side to side play. Another thing to check, since you describe the side play as minimal, is a bent trigger post. I doubt that that's the problem. It might be time for a trip to the Smithy.

The side to side play does not bother me, it's very minimal. I was just woundering if it would cause this issue.

 

[IamCaleb]

With the side plate off I notice while cycling the action that the trigger seems to release the stop fairly quickly (before the arm pushes the cylinder over). Could it be a timing issue? If so, how is this adjusted?

 

[Stophel]

The cylinder stop probably is bent, has a burr, or something that hangs it up when the trigger is pulled just so. A good gunsmith would be able to see exactly what is the problem, and should be able to fix it quite easily.

 

[jimmyj]

???
1. bent trigger post
2. weak trigger stop spring
3. weak or no hand spring
4. front of trigger not engaging the trigger stop.
(a) replace trigger stop and spring before doing anything else.

 

[IamCaleb]

For $12 from Midway, I think I will replace the cylinder stop and spring first. If that does not work, off to the smith it goes.

 

[cmj8591]

It is, most likely, the cylinder stop bearing surface that interacts with the trigger to make the stop retract into the frame. It may also be the trigger. Try replacing the stop first as that is the cheaper repair. Also, put the factory springs back in when you do the repair. Once you get it working with the factory springs, then try the wollff springs.