Slide locked open after firing, on a non-empty magazine twice, then locked open & jammed - wouldn't release.
I asked one of the range employees to take a look at it. He fiddled a bit, then braced the slide release against the edge of the counter and pushed on the frame to release the slide. The slide release lever was no longer being pulled down away from the slide by spring pressure.
I took it home, cleaned it, and set it aside till today to disassemble.
What I found really surprised me - it wasn't a spring failure, and while the spring was no longer engaged w. the slide release lever, it was because - metal failure! There's a little 'hook' or extension of the lever that the spring engages with. That tiny metal hook had snapped off.
Here's someone else's shot, which shows how it's supposed to work:

I'll head off to S&W to see about a replacement lever.
