Locks
I have owned a few with them.
And a bunch without. Never had a malfunction caused by one but still don't want one on my gun.
I have never met a guy who wanted one ! It's an un needed feature that serves no purpose. I now own 2 S&W revolvers.. A model 29-2 and a model 34-1. Both 4". As far as I am concearned the old pinned and recessed Smiths are best. I know of a 3" model 36 I want and if it is still there when I get my tax return it will make 3 ! Tj3006