Revolver smithing

[flatbutt]

The DA pull on my SW 686 is really heavy. I've been searching online (Miculek comes up alot) for the process to lighten the pull but there is some confusion in my mind on this.

Making the pull lighter (not smoother) seems to result in light strikes. I'm not sure how changing that main spring causes lighter strikes, but apparently it does. So I'm wondering if anyone here can help 'splain this to me and/or tell me if I can lower the DA pull weight and not deal with FTFs.

Mr Higgins are you open?

[KFC911]

Higgy will tell ya those DA spoons are pure evil

[flatbutt]

bump

[Jeff Higgins]

When you are pulling on the trigger to cock the gun by firing it in "double action" mode, you are compressing the mainspring that powers the hammer. The correct term for this is actually "trigger cocking", which is more descriptive of what is really happening. The other method of cocking is, of course, to simply pull the hammer back. So, in essence, these guns have two modes of operation - trigger cocking and hammer cocking - hence the term "double action". A bit of a nit-picking point, but it does kind of illustrate things a little better. A "double action only" revolver, one missing the hammer spur so that it cannot be cocked with the hammer, is technically "trigger cocking only" and, therefore, really a "single action". But I digress...

One of the unfortunate qualities of a "double action" revolver is that when the trigger is used to cock it, it does not force the hammer all the way back before releasing it. In other words, the hammer only goes about 3/4 as far back as it would be if you simply cocked the hammer. This in and of itself shortens the hammer throw enough to lighten the strike on the firing pin a good deal. The mainspring needs to be heavy enough to be able to drive the hammer with enough force from this "less than fully cocked" position so, unfortunately, they can be a bit heavier than we like.

Your 686 should have a tiny little adjustment screw at the front of the grip frame, where your pinky would be. This is meant to be used to vary the tension on the mainspring, and thereby either add weight to or lighten up the trigger cocking pull. Back it out too much, though, and it will start to suffer light strikes in trigger cocking mode. I've found my Smiths need this screw about as tight as it will go to ensure trigger cocking reliability.

I've found a good solution to be one of the Wolff spring kits. These lighten the action up considerably while still providing reliable ignition in trigger cocking mode. The mainspring is a different thickness profile, so I think it changes the places in the hammer travel where it gets heavy or light. Try one, they're cheap and easily installed.

https://www.midwayusa.com/product/1004171994?pid=222267

[flatbutt]

Originally Posted by Jeff Higgins

When you are pulling on the trigger to cock the gun by firing it in "double action" mode, you are compressing the mainspring that powers the hammer. The correct term for this is actually "trigger cocking", which is more descriptive of what is really happening. The other method of cocking is, of course, to simply pull the hammer back. So, in essence, these guns have two modes of operation - trigger cocking and hammer cocking - hence the term "double action". A bit of a nit-picking point, but it does kind of illustrate things a little better. A "double action only" revolver, one missing the hammer spur so that it cannot be cocked with the hammer, is technically "trigger cocking only" and, therefore, really a "single action". But I digress...

One of the unfortunate qualities of a "double action" revolver is that when the trigger is used to cock it, it does not force the hammer all the way back before releasing it. In other words, the hammer only goes about 3/4 as far back as it would be if you simply cocked the hammer. This in and of itself shortens the hammer throw enough to lighten the strike on the firing pin a good deal. The mainspring needs to be heavy enough to be able to drive the hammer with enough force from this "less than fully cocked" position so, unfortunately, they can be a bit heavier than we like.

Your 686 should have a tiny little adjustment screw at the front of the grip frame, where your pinky would be. This is meant to be used to vary the tension on the mainspring, and thereby either add weight to or lighten up the trigger cocking pull. Back it out too much, though, and it will start to suffer light strikes in trigger cocking mode. I've found my Smiths need this screw about as tight as it will go to ensure trigger cocking reliability.

I've found a good solution to be one of the Wolff spring kits. These lighten the action up considerably while still providing reliable ignition in trigger cocking mode. The mainspring is a different thickness profile, so I think it changes the places in the hammer travel where it gets heavy or light. Try one, they're cheap and easily installed.

https://www.midwayusa.com/product/1004171994?pid=222267

Great! Good stuff thanks Jeff! That makes it much clearer.

[masraum]

I'm pretty sure that was just a lucky guess.

[id10t]

Is it at least smooth feeling on the DA pull? If it is just weight, some "tricks" that will make it feel like less -

Smooth trigger face
A wider trigger face (or add a shoe to the trigger) will give more surface area and while not changing the pull will make it feel less.

Tyler Manufacturing and Distribution Company, Inc

[flatbutt]

Originally Posted by id10t

Is it at least smooth feeling on the DA pull? If it is just weight, some "tricks" that will make it feel like less -

Smooth trigger face
A wider trigger face (or add a shoe to the trigger) will give more surface area and while not changing the pull will make it feel less.

Tyler Manufacturing and Distribution Company, Inc

It's a VERY heavy pull but smooth.

[rfuerst911sc]

I say it's worth adjusting the factory tension screw as it costs nothing . Back it out 1/2 a turn and see how it feels . If it feels good fire some rounds to make sure you are not getting light strikes . I also have a 686 and may play around with that adjustment .