View Full Version : S&W M40/640 action job

December 16, 2001, 04:03 PM
Took apart my 640 and did the usual slicking of slide and deburring of frame . Also smoothed the sides of trigger,hammer and took 1 1/2 turns off the rebound spring and hammer spring. HOW FAR can I go removing turns on the hammer spring? I don't have a spare....THANKS...dewey

John Lawson
December 16, 2001, 07:06 PM
You will be in immediate trouble if you clip coils off the springs. Refer to the Wolff catalog for replacement springs of lighter gauge wire allowing full motion, which you often don't get when you clip coils.

December 16, 2001, 07:27 PM
Listen to Mr. Lawson; he's one of the top professionals in the world.

(Not sucking up; got some of his articles on my shelf. Love the 9x21 conversion for carry.)

December 16, 2001, 08:40 PM
stupid to ask NOR to listen. BEST....dewey

December 16, 2001, 10:28 PM
Interesting. Kunhausen advocates cutting of stock Smith n Wesson springs over replacing them with aftermarket springs.

No opinion on this one...just find it interesting.


Mike Irwin
December 17, 2001, 11:38 AM
Hey Sam,

Opinions are like Smith & Wessons. Everyone has one.

I don't like the concept of cutting springs, either, just as I don't care for backing out the strain screw.

December 17, 2001, 01:35 PM
the first thing you should do is get another main spring...never cut a spring unless you have a spare already on hand. my personal inclination is to leave the rebound spring alone...i want that trigger to snap back as fast as it can.

smoothness always beats out lightness in an accurate DA trigger pull