how to fit a strain screw?

[MR.G]

I have a new strain screw for my 686-6 which is longer than the original one, and needs to be fitted. What is the proper way to fit a new strain screw?

 

[Sarge1644]

Strain screws are adjusted in length to provide proper mainspring tension. This is done by weighing the strength of the spring with trigger pull weights. If you don't have a set of weights, let a Smith armorer show you how to do it. Any other method is just guessing.
Sarge

 

[Nightowl]

Are you having problems with the original?

 

[MR.G]

I bought the gun used, and the original strain screw appears to be filed. I put a Wolf Power Rib mainspring in the gun, and the screw goes into the rib making it even shorter. Also the rebound block just touches the mainspring when cocked single action. The gun shoots fine with no light strikes, and has a light and smooth trigger pull.

 

[OKFC05]

With the power rib spring, I use full length screw--just happens to be right.

 

[MR.G]

OKFC05,
Do you use the use the factory replacement, without shortening it? I tried the screw, without any modification, and the trigger pull is good. The new screw has a rounded end that fits in the rib of the Wolf spring pretty good. Also it clears the rebound block now.

 

[BillyWayne]

I use the rounded longer screw with the ribbed Wolff spring and the shorter flatened screw with the flat factory or Wilson Combat spring.

 

[MR.G]

Thanks for the replies. I am going to use the new factory screw without shortening it. It is a little bit longer, but with the rib in the Wolf mainspring it is probably ok.