Ruger GP 100 issue

Took my ruger GP 100 to the range about a week ago. After about 12 rounds the gun malfunctioned. The trigger had barely no resistance. The cylinder would spin but the hammer would not move in double action. I played with the trigger and hammer. After a few minutes it started working again. I took it home and cleaned it. I cleaned the trigger return spring tunnel out, although I did not disassemble the trigger assembly
Went to the range yesterday and the same thing happened after only 5 rounds. One of the Rso’s came over and looked it over. Said he’s more familiar with S&W’s and it was strange. When I got home it suddenly started working again.
The gun was purchased new about 10 years ago but has less than probably 300 rounds through it.Gun is all stock including springs. Any ideas? I would rather not have to send it back to ruger.

Jack

One thing I did notice is the trigger return spring had what appeared to be maybe light surface rust. The texture did not feel smooth.

The hammer does lock back in single action mode. When I got the gun back home everything is operating again just like the first occurrence.

Yes, the cylinder would spin freely but hammer was not moving. After talking with Ruger customer service they are going to send me out a trigger return spring. They will not pay for shipping because of the age 2009. If the spring doesn’t work than I will send it in. When I got the gun home the revolver is working again. Dry fired it and cannot get it to duplicate.

The cylinder would spin and lock with each pull of the trigger, but no hammer movement.

After studying the action, I have come to the same conclusion as you. Ruger is sending a new trigger return spring. Hopefully my issue goes away. When I disassemble it I will also see if the hammer dog spring is ok.

Thanks!

Update: FYI I replaced the trigger return spring and that solved the problem. Shot a little over 100 rounds through it and no issues. Thanks to all those with suggestions.

jack