629 Trigger sticking half-way

[Arman4461]

Hello folks,
I have a few model 29s, and they have been faultless in operation. However, my 629 no-dash 4" has a habit where the trigger seems to stick about halfway through its travel, which ties up the action. When it does this trick, I push the trigger forward and the action returns to normal. I have taken the sideplate off and lubricated the action with CLP to no effect. I initially assumed the problem was caused by the rough extractor star on this pistol, which has the roughest machining work I have ever seen on an S&W. If anyone knows where a Blue extractor star for a 29 no-dash can be found, I would be willing to buy it just to get a smooth extractor star. I tried the extractor from my 29-2 and it would not allow the cylinder to close, so I cleaned it up as best I could and re-installed it, but I aint happy with the look or feel of it. I rambled on, but if anyone has an idea why the trigger gets bound up, please let me know the secret code word
Thanks!
Arman4461

 

[Alk8944]

If it does everything right except the trigger recover the most likely problem is the rebound slide spring has been cut and it just doesn't have enough power to do it's job.

Disassemble the gun and check the rebound slide spring, it should have closed coils on both ends. A new spring is approximately 17 coils and 1 3/16" long. If yours is shorter than 15 coils or approximately 1 1/16" long it needs to be replaced.

 

[JohnK]

While you have it apart, polish (only) the sides of the rebound slide, with a hard, flat, Arkansas stone.

If their are any obvious dings, scratches, etc., in the side plates where the rebound slide lives, polish them also. A little goes a long way.

 

[swmod29]

I would also try lightly beveling all the edges of the rebound slide.

 

[500 Magnum Nut]

Like Alk8944, I'd find a proper 18LB spring. That will certainly correct any drag or binding. After a little polishing and a drop of gun oil, you could reduce the poundage a little if desired.

 

[Arman4461]

Thanks guys--
I will do as suggested today. I don't know why anybody would mess with the rebound spring? It is one of those that had the strain screw backed out, another trick I don't understand, since I am a Colt Python freak mainly. I tightened the strain screw up. Everything but the trigger return is perfect, and it is an accurate little hand cannon. Thanks for the ideas!
Arman4461

 

[ronnie gore]

629

i had the same problem with a s&w 36, it was the rebound spring someone had shortrned, after replacing the spring ,no more problems.

 

[scooter123]

Thanks guys--
I will do as suggested today. I don't know why anybody would mess with the rebound spring? It is one of those that had the strain screw backed out, another trick I don't understand, since I am a Colt Python freak mainly. I tightened the strain screw up. Everything but the trigger return is perfect, and it is an accurate little hand cannon. Thanks for the ideas!
Arman4461

Reducing the strength of the rebound spring is one part of an "action job", which is done to reduce the trigger pull weight and smooth the feel of the DA trigger stroke. As you have found out, when you go too far the result is a trigger that won't return properly.

One commonly overlooked feature that should be added during an action job on an older S&W is adding a chamfer to the corner of the rebound slide between the 2 faces that rub against the frame. This will eliminate any "corner drag" caused be a small raduis in the frame remaining from the machining operation that forms the two surfaces the rebound slide rides against. BTW, on the newer MIM guns the rebound slide is made with a radius on this corner, so the new guns incorporate features learned from years of gunsmiths tuning these guns. If your rebound slide is dead sharp at this corner, it will help a great deal to add a 1/32 inch radius or a chamfer with a 1/32 wide flat to this corner.

As for the power of the rebound spring, I've been recently experimenting with the action in my models 610 and 617, mainly because I am a tinkerer at heart. What I have found is the rebound spring can have a distinct effect on the trigger pull, in both Single and Double Action. Brownells sells a kit of rebound springs in a range of 12 to 15 lbs and it's been interesting to experiment with what works and what doesn't. What I found out pretty quickly was that while a 12 lbs. spring will work perfectly during a function test, and reduce the SA trigger pull to about 2 lbs, it will cause a gun with some recoil to tie up during live fire. In my 617 a 12 lbs spring works just fine, in my heavier recoiling 610, a 12 lbs spring caused the gun to fail to reset properly in 2 out of 48 rounds sent downrange. So, now my 610 has a 14 lbs. rebound spring installed and yesterday it functioned perfectly during live fire. Point is, what works properly is, in my experience, partly dependent on the caliber and recoil of the gun.

Finally, I'll also note that Brownell's sells a special tool for installing the rebound spring that I consider a MUST HAVE. In fact, I would not recomend doing anything with your rebound spring until you have that tool in hand. Otherwise you will be bald from tearing your hair out with the frustration of trying to install the rebound slide without that tool.

 

[Alk8944]

I tightened the strain screw up. Everything but the trigger return is perfect, ....Arman4461

Arman,

This is exactly what points to a too light rebound spring. If they backed the strain screw out instead of using a lightened mainspring chances are they cut the rebound spring too instead of installing a lighter one.

One other way to verify this. When the trigger fails to recover pull back lightly on the hammer spur instead of pushing on the trigger. I will bet that almost as soon as you touch the hammer the trigger will snap forward.

Unless you intend to shoot the gun double action just put in standard springs and keep the strain screw tight. All the playing with springs accomplishes, at best, is a 1/2 to 1# reduction in the single action pull.

I usually don't explain myself, but to establish a foundation for my remarks I have been a working gunsmith, Police armorer, a working LEO, and have attended the S&W Armorers School, from 1962 to date. I have been working on S&W revolvers from the beginning.

 

[Arman4461]

Well guys, the verdict is in. Guilty party (former owner) cut a snip off of the rebound slide spring. Looks like I will again take the advice given, and buy the tool for installing the spring and the spring kit to do a little tinkering. Good thing I pack a Python and not a 4" .44 Maggie
Thanks so much for the excellent long-distance troubleshooting and advice. Perhaps you can tell me why my Vette stumbles when approaching 185mph on a high speed run down I-10 if the outside temp is above 70F
I appreciate the kind help....Arman4461

 

[ms]

Thanks guys--
I will do as suggested today. I don't know why anybody would mess with the rebound spring? It is one of those that had the strain screw backed out, another trick I don't understand, since I am a Colt Python freak mainly. I tightened the strain screw up. Everything but the trigger return is perfect, and it is an accurate little hand cannon. Thanks for the ideas!
Arman4461

The balance between the two springs matters. You might be able to adjust the main spring lighter so that the trigger will reset, and the gun will still fire reliably. If you do choose this option the strain screw should be shortened so that it can be tightened fully and not work loose.

If you need 100% reliability you should use full strength springs.