S&W model 14-3 sear issue please help!

As you can see, re-engaging the DA sear happens very late in the return, so it's important the trigger fully return fully and under all conditions (IOW, you shouldn't have to let it out quickly to reset). Your issue could stem from a number of things, but top of my list is either a rebound spring that's too light for the mainspring and/or a DA sear that's a smidge too long.

If the SA trigger feels scary light (assuming you know what normal and "scary light" for a S&W revolver is), it's possible someone swapped out the rebound spring for one that's too light. A trigger gauge really ought to be used. If you do have a trigger gauge, measure both the DA and SA pull weights. If the revolver is stock, they ought to measure approximately 11-12 and 3-4lbs, respectively. If someone swapped the springs, the weights might be lower, but the DA:SA pull weight ratio should, IME, be in the area of 2.5-3:1 (I call it 2.8:1). A ratio that's notably higher than this would reflect a relatively light rebound spring.

A DA sear that's a smidge too long has trouble resetting past the hammer nose. You can see how this might be so in your first pic. A qualified gunsmith really ought to make this call and do the work, if needed.

There could also be a burr somewhere in the action. Again, a gunsmith could make that call.

I will third taking a liik at the rebound spring first. Get the rebound spring tool from Brownells or Midway. It will make life a lot easier for you.

a rebound spring that's too light for the mainspring

Never keep full tension on the Mainspring with the side plate off, it can bend the Hammer pin which would require professional repair.

Be careful when polishing sear surfaces, especially the single action shelf. I wouldn’t even touch that one. I would only recommend polishing if the spring change doesn’t work and that’s if you know what you are doing. If you don’t feel confident, leave that part foe the gunsmith. I have worked on many S&W revolvers myself but I only attempt what is in my scope of capabilities. Keep us updated on the situation after the spring arrives.

I had a trigger problem once and discovered the strain screw had backed out just a little bit. Tightened it up and it got fixed. It was less than half a turn.

Congratulations. That's a "feel good" moment.

Glad you got it fixed. The original pictures looked like it was drenched in oil or is that just the way the pictures turned out? I know it had nothing to do with your problem, but I'd be worried all of that oil would run out and get on something it shouldn't

FWIW:
Polishing all the internal parts with jb bore paste & a cloth wheel on a dremel tool including the rebound spring. Then using heat & treating them with moly paste.


Doing this lightens the trigger pull #+, increases the lock time of the revolver while maintaining excellent primer hits.

Typically we'll take a s&w revolver and tighten the strain screw down all the way then back it out a 1/2 turn and test loads with federal primers. If they go bang the strain screw gets turned out another 1/2 turn and then re-tested with federal primers. We wash-rinse-repeat this until we get lite fp hits/can't ignite federal primers. Count the # of 1/2 turns it took to get the lite strikes and write it down. The the revolver gets taken apart and all the internals polished and treated with moly. Then the revolver gets re-assembled and if needed shims installed. Put the strain screw in all the way and then back it out the # of 1/2 turns it took to get lite strikes on the federal primers and re-test.

I have yet to see a revolver not set off the federal primers after the rework/polishing/moly treating of the internals.

forrest r said:

FWIW:
Polishing all the internal parts with jb bore paste & a cloth wheel on a dremel tool including the rebound spring. Then using heat & treating them with moly paste.
View attachment 826645

Doing this lightens the trigger pull #+, increases the lock time of the revolver while maintaining excellent primer hits.

Typically we'll take a s&w revolver and tighten the strain screw down all the way then back it out a 1/2 turn and test loads with federal primers. If they go bang the strain screw gets turned out another 1/2 turn and then re-tested with federal primers. We wash-rinse-repeat this until we get lite fp hits/can't ignite federal primers. Count the # of 1/2 turns it took to get the lite strikes and write it down. The the revolver gets taken apart and all the internals polished and treated with moly. Then the revolver gets re-assembled and if needed shims installed. Put the strain screw in all the way and then back it out the # of 1/2 turns it took to get lite strikes on the federal primers and re-test.

I have yet to see a revolver not set off the federal primers after the rework/polishing/moly treating of the internals.

Click to expand...

2 questions. How long does the moly treatment last? And I didn't understand the part about using shims if needed. What kind of shims and is there something you are doing that might create the need for a shim? I got lost somewhere.

Moly will last the life of the firearm and a lot longer. This is different than shooting moly coated bullets or using moly lube on cast bullets. And unlike the coated moly bullets/moisture issues, there is no issues when treating metal this way Doing this the moly penetrates into the metal forming a lube layer a lot like sharks skin.
Traditional vs sharks skin:
Take 2 pieces of 1" flat stock steel and polish/mate the surfaces. Their contact point/friction point will be 1" wide. Take 2 1" files and knock the sharp edges off of them and polish/mate the surfaces. Even though the files are 1" wide they will only have 1/2" of contact point/friction, hence shark skin.

Automotive engines are an excellent example of what moly treated metal brings to the table. No break in 3x+ the millage before rebuilds.

I either make my own shims or buy them, typically it's a combination of both. Shims look like small washers and are very in thickness, 2/1000th's, 4/1000th's, custom, etc. They are used to lower rub/friction points along with centering the hammer & trigger to their mating surfaces.

If you have a trigger group apart and polished/inspected everything, take the extra step to moly and shim (if needed) that trigger group. The difference between a simple polish and re-install and a polish/moly/shim/hand fit will easily take another #+ off the trigger pull.

Anyway, moly is 1 of those products out there that most people see moly & bore in the same sentence and automatically turn away & never look back/give it a second thought. Trigger groups benefit from it. I've had fantastic results re-working the bolts on bolt action rifles and moly treating them, had as much as a 40% reduction in group size & the increased lock time is a bonus. Cuts down the wear on semi-auto bolts and is excellent for the fp/fp channel. Get a 1911 right & tight then treat the bbl lugs and the bbl/bbl bushing contact point.