How many of the brethern here have actually experienced a problem with a S&W frame lock revolver? I did a quick search and found one report where somebody said his steel-frame had spontaneously locked when he dropped it about four feet onto a concrete floor. Massad Ayoob wrote a nice piece about his take on it which you can find at Massad Ayoob >> Blog Archive >> INTERNAL GUN LOCKS. He mentioned that report and that he'd heard of a number of stories regarding light alloy frame revolvers locking that way when fired with extremely hot loads, but had done a lot of that kind of shooting with one he's owned for years and never had an issue. His solution (and mine) is to have and carry the old-style revolvers for social purposes and keep the others for target and hunting, but, like most people who carry a wheelgun for self-defense, we're both clearly suspenders & belt types. He also discusses the wisdom, or lack thereof, of removing the lock on a carry gun. It's worth a read. Meanwhile, from what I've seen, most of the "spontaneous lock" stories out there that I could find were things that happened to the second cousin of somebody the teller met in a bar. I'd be interested in firsthand accounts.