Meditation upon S&W Revolver Lockwork

[HammerBite]

When I look at the lockwork of a Smith and Wesson revolver, it appears to be very simple. If I exclude the hammer block and various springs, plungers, pins and studs, I count only six functional parts.

Appearances can be deceiving.

If I list the six parts and the functions they perform, I get the following:

1. Trigger
   1. Elevate double action sear during first part of DA pull.
   2. Pick up hammer from double action sear during last part of DA pull.
   3. Drop hammer at end of DA pull.
   4. Restrain hammer when cocked for SA.
   5. Drop hammer after SA pull.
   6. Elevate hand during back stroke.
   7. Lower hand during return.
   8. Retract cylinder stop during back stroke before beginning of cylinder rotation.
   9. Release cylinder stop during back stroke before cylinder indexes with barrel.
   10. Push rebound slide rearward during back stroke.
2. Hammer
   1. Rotate trigger rearward while being cocked.
   2. Strike firing pin after falling.
3. Double action sear
   1. Rotate hammer rearward while being elevated.
   2. Move out of trigger's way during trigger return so that sear may be engaged.
4. Cylinder stop
   1. Engage cylinder notch when extended.
   2. Move out of trigger's way during trigger return so that stop may be engaged.
5. Hand
   1. Rotate cylinder during ascent.
   2. Engage next cylinder ratchet position during descent.
6. Rebound slide
   1. Cam hammer back when forward.
   2. Raise hammer block while moving rearward.
   3. Lower hammer block while moving forward.
   4. Transmit motive power for trigger return.

Notice that the six parts perform a total of 22 different functions, and they perform those functions in the correct sequence and with the correct timing.

Your list may differ from mine, but you have to admit that gun designers are a pretty clever bunch; many things get done by few parts.

I wonder what kind of mess I would have come up with if I had designed a DA revolver without ever having seen a revolver.

 

[Dienekes]

S&W should probably put a copy of this in the box with every new revolver, along with an appropriate curse on anyone inclined to "improve" the gun. If it ain't broke...