I think I have resolved an issue I had recently, but I need some input from someone who has experience or knowledge of the problem I had. Here's my story:after 25 years without a SMITH, using sig and baretta, I recently obtained a 29-2 that was traded in by an elderly man for a rifle. The pistol truly had been fired no more than 50 times. I got it, shot 24 rounds and took it home, cleaned it and relaxed the hammer spring screw 1 1/2-2 turns. Next time to shoot, in single or double action use it would be hard to work or lock until I relaxed the tension and then it could complete the cycle. I could feel that there were parts interferring with each other in side. The feel of the resistance seemed different on each failure. Watching the action with the side plate removed, I saw the cylinder lock on the bottom bind with the trigger front sear, the hammer bind at the sear, so on and so forth. I traced it all back to the hand which rotates the cylinder. I then thought that it was cut too short to fully rotate the cylinder to lock up. Then, I tightened the hammer spring up to it's original place and so far, after 100 dryfires, both single and double action, it seems o.k. Haven't shot it yet.
So, is it as simple as my lessening the tension on the hammer spring that could cause my problem? In my college years I and my hunting buddies had Smiths, and I could do anything to and with a K frame. I never had this kind of a problem like this, many years ago. Please bring me up to date. Thanks

Welcome to the Forum.

I'm not a Gunsmith but I was told in the very beginning to leave the main spring alone - that screw is to be tight at all times.
Everytime I've seen or heard of a problem regarding this - it's because someone tampered with the screw (shortened it or wedged something behind it, etc..)
Needs to be tight (period)

I agree with leaving the mainspring screw TIGHT!
It is not the correct way to lighten the action up. Buy a Wolffe spring kit for that.

Also, working the action with the sideplate off is not a good idea since the parts can, and will raise up from their proper location/alignment with each other. They can be damaged, or bind with each other leaving a false impression that something is wrong when in fact it isn't.

When you loosen that screw, you, in effect, make the spring LONGER.

It can/will bind then.

__________________
NRA Instructor

Thanks so much guys, I have learned a lot with this particular gun. I love it and it is accurate. When I first fired it, I put 2 in the red dot and 4 around it for a 3 inch group at 15 yards. I used some Hornady HP's left over from a ruger years ago.
Evderything you guys said makes perfect sense now and the last comment about loosining the screw makes the spring longer-so obvious but I was so oblivious to that. Thanks again.