Wandering cylinder stop spring - solution?

[Easy]

After a lengthy search I recently bought a five inch M27-2. Love the gun, very accurate and IMHO one of the nicest N frames made by S&W. This gun replaces a five inch M27-2 I foolishly sold a while back.

My only concern is twice now, while shooting, the gun has gone into a condition where the trigger is sluggish to return forward after firing a shot. I know the cause...but not the solution. Each time I have taken the side plate off and noticed that the cylinder stop spring has drifted from its proper position at the end that contacts the frame and that part of the spring is bent out of position, partially jamming the cylinder stop and preventing the trigger from moving forward into its rest position properly. I have used a very small flat screwdriver to straighten and nudge the base of the cylinder stop spring to where I think it should be in contacting the frame and the gun works perfectly - for a while. But since the spring has worked its way out of position twice before I am sure it will do it again.

Is this a common problem? Is there a fix?

I will soon be ordering a new cylinder stop and a couple of springs hoping that will solve the problem. My concern is that it has come loose at the frame end - not the cylinder stop end. I have not taken the cylinder stop out of the gun yet. Is there some type of groove or hole in the frame that should be holding the cylinder stop spring in place?

Thank you.

 

[Alk8944]

Easy,

Sorry, but what are you referring to as the "Cylinder stop screw"? Up to the -1 there was what is commonly referred to as the "Trigger guard screw" which retained the cylinder stop spring and plunger. Re-design of the cylinder stop, which is designated by the -2 eliminated all these parts except the spring. You cannot, obviously, "push" a screw into position unless it is being bent. Since you use the word screw at least 4 times I have to assume that is the word you meant to use.

I suspect the spring itself is bent, which can happen on re-assembly if you are not careful, and it is being stressed when you push it straight. As the cylinder stop works the spring simply pops back to it's least stressed (bent) position, with the end which is against the frame moved back toward the sideplate. Correct? Replacing the spring with a new one will fix the problem if this is it. Don't try to change the cylinder stop, it is a fitted part and not nearly so simple to change as it may appear.

When you change the spring you will need to completely disassemble the lockwork, the cylinder stop is the last piece to come out of the frame. When installing the spring put the stop back on the pin half way and then insert the new spring in it's hole in the stop. Using a small screwdriver compress the spring enough to allow it to clear the frame and then push the stop and spring down enough that the spring is trapped by the frame. Use the screwdriver and push the stop and spring fully into the frame together. If you try to just push the stop there is a good chance of kinking the spring and you will be right back where you are now.

There is no notch, slot, stud or dimple for the frame end of the cylinder stop spring, it just needs to be pushed to the center of the frame so it is aligned with the center of the cylinder stop. It will stay put without any problem as there is no stress acting on it which would tend to move it out of position, so long as the spring is not damaged during installation! It has worked just fine this way for nearly 50 years.

To answer your question, if this is common? This particular problem is not at all common. Parts being damaged by improper assemble/dis-assembly by people who do not know what they are doing, with all sorts of firearms, is extremely common. It is amazing how many people who are afraid or unable to change the oil or replace spark plugs in their car think they are capable of making any sort of repairs to firearms. Go figure.

 

[Easy]

Thank you Alk8944!

Man is that embarassing. Must be old age creaping up on me. I could understand substituting the word screw for spring once... but four times!

I've gone back and edited the OP...but at least Alk8944 you were able to see through my befuddlement and give me the answer I needed. Yes, I am sure someone who didn't know what they were doing kinked the cylinder stop SPRING on reinstallation and it is now jumping out of position when the gun is used. I will order several springs (I like to have spares on hand in case I don't get it right the first time) and replace the bad one using the method you suggested.

And thank you for the heads up on the cylinder stop being a fitted part. I won't replace that. I was wondering if I would be asking for trouble trying to replace that part.

I agree completely with your view of backyard gunsmiths and the mess they can make of their firearms. Personally, I have been known to do the occasional oil change and tune up... and I am not afraid to tackle gun disassembly/reassembly. But I am also not afraid to ask questions when I am getting into an area where I don't know what I am doing. That is why this site is so great.

You have been most helpful. Thank you very much.

Easy

 

[Easy]

Fixed!

Thank you again Alk8944.

The replacement cylinder stop spring arrived in the mail yesterday and was installed as per your excellent instruction this morning.

I am absolutely sure you have diagnosed the problem and it is fixed. The old spring has a visible twist in the last two segments that is no doubt the result of some ham handed person forcing it into place during an improper installation. By using a tiny screw driver to compress the spring it slipped into place undamaged.

While I had the lockwork entirely out of the gun (a first for me by the way) I took the opportunity of cleaning out 37 years of built up gunk and grime.

The result is a buttery smooth action as good as the day it was put together by the visored elves on the benches at Smith and Wesson many years ago. No creep or drag. It breaks cleanly and the hesitation I experienced as the trigger returned forward after firing is completely gone.

To say I am a happy camper is an understatement. I now have my newly acquired five inch 27-2 just the way I want it.

 

[Alk8944]

Glad it worked for you.