629 classic parts question

[blackflyguy]

I removed the sideplate from my 629 classic serial number BSA58XXX and saw something i never saw on a S&W revolver. There is a slot cut in the frame going up and down from above the trigger to the slot for the cylinder release/bolt. In that slot rides a small metal "tab" with a slight bend at the top. It's connected to the trigger/hand and moves up and down when the hammer is cocked. What does it do? The gun functions fine without it. Is this a floating hand?
Thanks All.

 

[scooter123]

That is the "bolt lock", which is part of the Endurance package. Some shooters had problems with the cylinder unlocking under recoil so S&W came up with that Bolt Lock to prevent that from happening. BTW, on a S&W the Bolt is the part the thumb release is attached to and the Cylinder Stop is what Colt called the Bolt. Somebody should write a cheat sheet so we can keep up on the variety of terms between S&W and Colt. IIRC what S&W called the S&W 38 Special was referred to by Colt as the 38 Super Police, bet that caused a lot of confusion and a few arguments back in the day.