Model 29 Main spring replacement

[robmoss]

Hi All,

I had posted a few weeks ago about a misfire I had with a Model 29 I purchased recently. After much deliberation and advice from this forum I called S&W and ordered up a Main Spring and Strain Screw. I could not order a hammer nose as they are obsolete, which leads me to wonder what happens if you do break the pin. Or maybe I have it all wrong.
Back to the story at hand.

I removed the Main Spring and Tension Screw and did a comparison. The parts that were in the revolver are NOT Model 29 parts. The Main Spring it had has a different bottom end that is tapered as opposed to the part I purchased from S&W which is the same thickness from the halfway point to the bottom. The Tension Screw that came from out was maybe 1/4 of an inch longer than the part I purchased from S&W, and the head was maybe a 16th of an inch deeper.
I replaced the Main Spring and screwed in the Tension Screw till it just touched the Main Spring.
Now the trigger pull is massive. Ten pulls on the trigger and my finger is hurting. I can still feel it now. The cylinder spins and locks and the timing seems OK but the hammer takes a good deal of force to cock for single action and as I have said the pull is very heavy. The single action trigger works but seems stiffer than I had anticipated.

Does anyone know what kind of pull I should expect in double action? At the moment it is a strain to hold the sights steady as the trigger reaches the end of it's pull. I remember my Model 19 being like butter in comparison to this. I am sure that I have fit the parts correctly and I even put the spring and screw that came with it back in to ensure I was doing everything right.

Right now I am assuming that the revolver was not useable till someone put in a much weaker Main Spring just to get it to cycle. I guess I need to get a gauge to measure trigger pull.
So what do you think? Have I bought an $800 paper weight?

Best regards,

Rob in Texas.

 

[BoDog]

Get a Wolfe spring kit and forget it or take it to a good revolver smith.
I have done this with all my guns that aren't safe queens. Have had no problems.

 

[Kodakjack]

Is the original hammer intact? IF (and onlyIF) the hammer has been replaced the sear needs to be slightly ground down. I just completely re-did a Model 29-2. When I put in a new(old stock) trigger and hammer I had the same problem. The problem was not the spring but the new hammer slightly binding with the sear. You didn't say what model 29 it was..

 

[ken158]

The screw is "adjustable" by someone in the know... by filing the tip but be sure to keep it tight as designed.

 

[dangt]

If you did exactly what you said, that is, after replacement of mainspring and its screw, you screwed it in " until it just touched the mainspring," you definitely need to go FURTHER. What you are getting is "knuckling," the mainspring is binding against the hammer in such a way that it is REAL tight/stiff at near the top of cocking. I'm surprised you can cock it at all.

You really need to turn the screw in the entire way.....until it stops. You may find you can actually back out a half turn from here or three quarters of a turn from bottomed, but the proper way is put it in the whole way to bottom.

 

[dangt]

Sorry, I missed how old this original post is. I'm sure the problem is fixed by now ..... or gone down the road.

 

[gboling]

As I recall, the strain screw is fitted by filing until, when the screw is completely tightened, the trigger pull weight is correct. To get this right you need a copy of, The Smith & Wesson revolver, A shop Manual, by Jerry Kuhnhausen.

Too many "hatchet smiths" attempt "Trigger Jobs" by destroying the mainspring and strain screw.

 

[tlay]

Which mainspring did you order from smith? Do they have reduced power mainsprings like wolf? If it were me and I was NOT going to use this as a defensive use gun, I would put in a reduced power spring. As said before tighten the screw as tight as it will go, if it looks like you still have screw sticking out you may need to file some off. If you don't feel like you can do this take it to a gunsmith. Won't cost that much.

 

[tomcatt51]

Does anyone read the thread they're responding to? Or just the last post?

If you had you'd see this thread died 16 months ago, right after post #2. Same day as the OPs' last post.

 

[robmoss]

Funny stuff Tomcatt. Sorry I didn't get back with more info. I am afraid the 29 went into the safe and I cried over a beer and then got busy with other things. About a month ago I got it out and had a go again. I did a lot of comparison work with the 2 springs and 2 strain screws. The Knuckling issue diagnosis was right on the money. I am back to the original spring and strain screw backed off slightly from the max. This seems to work well and tested OK with some primed empty cases. It's not perfect so I may eventually call S&W and send it in for a service and a clean up. Thanks to all for their interest and assistance.
Best regards,
Rob in Texas.

 

[tomcatt51]

The Phoenix rising from the ashes. These guns came with DA trigger pulls that could be as high as 12 lbs. "Normal" probably being ~11 lbs. You can run a stock spring with too little preload from the strain screw and get into geometry problems with the hammer link "bottoming" against the hammer and the mainspring "buckling".