Been shooting my 686 4inch with wad cutters, and today
I got 3 or 4 FTF's in a row. I kept the hammer falling, and
all eventually fired. I tightened the mainspring screw in
the handle as far as it would go, but I don't think that had
much effect. Ideas about what's up here?

High primers???
Tightening the strain screw that you did would have been the other choice

I’d probably start with the ammo to determine if the primers might be poorly seated.

After that I’d examine the hammer nose or firing pin for damage.

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Mark Lathem

Did you, or anyone, replace the mainspring with a Wolff "Power Rib" spring? If so they need a longer strain screw than the factory one. Wolff doesn't mention this on their web site. Otherwise the strain screw may have been shortened. A new factory mainspring and strain screw should fix any problem with failures-to-fire that may be related to a weak or modified parts.

First try a couple different ammo's, if you have FTF, try the single action on those rounds, single action is a little stronger than double action, if you did not buy the 686 New, try a new factory strain screw, then if it has been fired at lot, try a new main spring, different ammo takes different Lbs. springs, if you have a gage check the Lbs., it may take around 8-9 Lbs. for some ammo brands, Federal is known for less Lbs.. Good Luck..

Does your model have the firing pin on hammer style or the floating firing pin on the frame?

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Waiting for the break of day

Yep. And in my experience, even with an extended firing pin, it's still not enough for the "factory standard power" mainspring to reliably ignite some of the harder primers like Winchester and foreign military primers in double action.

Check the primers, after waiting a bit, to see if it's a late firing pin strike. Check the firing pin for breakage, check firing pin protrusion through the recoil shield. I don't know if your 686 has a hammer mounted firing pin or frame mounted but the firing pin may be binding as well.

Boscoe Are these wadcutter load new or reloads .

Try a different brand of ammo maybe a premium load before there is something mechanical .

IF you still have ftf issues after trying a premium ammo than look to the main spring and firing pin .

A lot of bad primers floating around after covid, especially many of those from Argentina. Try different ammo before looking at the mainspring and strain screw. However, if it is a Wolff spring, even the standard strength version, it will often require a longer strain screw.

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213th FBINA

If your mainspring strain screw was not tightened all the way, just that 1/4 of a turn or more could make all the difference in firing/FTF! Also, you mentioned wadcutters, factory ones are very hard to find now, so I will assume reloads. When there is a FTF and then the ammo will fire on the next or repeated firing pin strikes, it usually indicates that the primer was not fully seated all the way to the bottom of the primer pocket. In my early reloading days, seating the primer to below the rim was the thing to do. I used to have several misfires. When I learned to seat to the bottom of the primer pocket, FTF's disappeared.

Fail to fire on guns with the hammer nose firing pin were rare, except on tuned guns or where the mainspring strain screw was backed out. It seems that with the frame mounted firing pin, many more failures to fire have been reported. It seems the factory firing pin was too short, and an aftermarket firing pin that was longer was the appropriate solution.
In other words, it could be ammo, it could be the gun! I have had a couple FTFs with S&B ammo this week, where the cartridge just would not fire, even after multiple strikes with full power springs! Dud primer!
It happens.

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Richard Gillespie
FBINA 102

OK, I have to ask....
Did it fix the issue or not?
There should be a definitive outcome if the issue was the mainspring screw.
Color me curious....

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.............SmithNut

Ok, these are handholds that fire 100% in my SW52. I bought the
pistol new years ago. It sat in the closet full of 357 Hp for many
years. No parts have been exchanged. I will take it down and do
a serious cleaning and see if that will fix it. It is the model that has a flat hammer striking the firing pin, so mabe it's gunked up.

This thread comes up at least several time annually. The responses are always pretty evenly split among those that modify/replace springs and find their guns function fine vs. those who modify/replace springs and their guns are unreliable.

Factory revolver springs may result in heavier trigger pulls than aftermarket versions, but I've found them to be 100% reliable during the last 50+ years with many, many revolvers, Colt and S&W. Shoot the guns enough to get used to the factory setup. It won't let you down. Seems like this would be of particular importance to the fantasy gunfighting aspirants.

Measure it's OAL" with a good caliper if you can while you have it out to clean it & inside it's tunnel.

S&W has had issues over the years with short or marginal length firing pins.

The preferred typical length is ~.492-.498".

If it's .485-.492" it could be suspect & worth changing out for a longer one.

After market firing pins from APEX or C&S run .500" & .510", respectively.

I like the firing pins with the broad rounded nose. I believe APEX changed back from the pointier (2016) version some years ago to the earlier broad rounded version.

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Waiting for the break of day

thanks I shoot SA only so I like a lighter trigger. I will se about getting the longer firing pin, that would tolerate a lighter SA trigger, would it not?

OH, now the facts come out


Reloads, 99% of the time the primers are not seated correctly
As they fired after repeated strikes sure seems like improper primer seating.

Try some different ammo

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Still Running Against the Wind