Lately, I have been shooting my .40sw s and I have a renewed appreciation of the round especially through the 229. An older one 3x ser #ed AB121xx has a loud trigger screech when trigger-pulling in double action. It is very annoying so I took it apart and changed every spring - from hammer spring to sear spring etc. well even though the ddbl action pull is lighter, it still screeches - like a rusty door hinge. There is no rust anywhere, the piece has been well maintained throughout the years, but how should I get rid of the screech? None of my other vintage sigs have the problem. And no, the screech does not affect the the operation or accuracy. My thanks in advance for your comments and suggestions.

I'd be inclined to check to see if the Trigger Bar was slightly bent and dragging across the frame, check to see if the Trigger Pivot Pin and the opening in the Trigger it fits through was clean and well lubed, and to see if the Hammer Strut was perhaps dragging against something during its travel.

I too think its the hammer strut dragging on the hammer spring.

It could be anything from a particle of debris (like a brass shaving) where it shouldn’t be to a damaged part.

This should be easy to track down, especially to someone familiar with the workings of the weapons parts. Take the slide assembly off and very slowly work the double action trigger pull- don’t let it break; pull and release before it drops the hammer back and forth and listen/feel for the cause of the noise. It will undoubtedly create vibration as well. Be VERY careful to trap the hammer with your thumb while doing so in the event you pull too far and the hammer lets fly- you don’t want it smacking the frame without benefit of the slide assembly in place and doing its job. See-saw the hammer back and forth and the origin of the squeak should become evident. Have oil ready to drip where you think you get it isolated; it will dampen the screech when applied.