Strain screw is ... ???

[FunYet]

It's been suggested that I check the strain screw on my S&W 620 to address my problems with light strikes.

Where is the strain screw. I'm not having any luck finding schematics online.

Thanks

 

[Chuck Dye]

First, do you have a 629? Can’t find info on a 620 . Most S&W revolvers have a leaf mainspring which is tensioned by a screw through the front strap of the grip frame at about the ring/pinky finger level. Light strikes and even action binding may result if the tension screw is not tight enough. Jerry Kuhnhausen, in his book on S&W revolvers, warns more than once to use a screwdriver that is slightly undersized to avoid frame damage. Implied is the possibility that a shortened tension screw (previous less than stellar gunsmithing) may cause problems.

Check that your tension screw is tight. If that does not do the trick, check for excess shortening and obtain a new screw if needed. Consider a copy of Kuhnhausen. See www.gunbooks.com

 

[Majic]

Jerry Kuhnhausen, in his book on S&W revolvers, warns more than once to use a screwdriver that is slightly undersized to avoid frame damage.

Understand he is talking about the width of the blade.

If you still have the stock grips on your revolver then remove them first. On the front strap (the part of the grip frame facing the trigger guard) you should see a screw. This is the strain screw and it applies tension to the mainspring. It can sometimes loosen under recoil (not often, but it has been known to happen). Just take an appropiate screw driver (gunsmith screwdrivers are best because they have square ends to fit the screw slot precisely where normal everyday screwdrivers have tapered ends) and see if you can tighten the screw.
Your 620 is a L-frame and all L-frames are alike so just look for stuff about a 686+ and it will be the same. The only difference in the new 686+ and your 620 is the barrel contour.

The strain screw is number 55 in this exploded view:
http://www.e-gunparts.com/productschem.asp?chrMasterModel=1980z686