After a short shooting session, yesterday, I noticed that the grips on my month-old 317 had worked loose. I could not get any tension on the grip screw, whatsoever. When I removed the panels I found several cracks radiating out from the receiving nut in the left panel. I don't believe I'd overtightened the screw since all was snug and fine before the session. This is an extremely light weight, J-framed .22. Has anyone suffered similar premature failure with the full sized, factory synthetic grips? Are they particularly fragile or delicate? This is my first S&W alloy framed, J-revolver. How sturdy are these grips?

I'm not aware of any defects in the factory grip design. Sounds like the pair you have may have a loose nut? You might try removing them and thread the screw into the grip panel with the nut and see if it spins.

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Centennial Every Day

The nut anchored in the left panel is completely disconnected and cannot hold the grip in place. It spins freely with each turn of the grip screw... S&W Customer Service is sending out a replacement panel(s), per warranty. No charge. That's impressive!

Hopefully this is just an isolated case. I ordered a pair from S & W for my older model 60, and so far I really like them. Mine so far have stayed nice and snug.

I've had a gaggle of those boot-grips....like the ones on the 442 and never had a problem. They use those same grips on other models, so it's not 317 specific.

You just got a pair that were defective and the captive nut is spinning inside that panel.

I bought a set of uncle mike boot grips from S&W last year. When they arrived, I noticed something was haywire and discovered that the "captive nut" in the LH grip panel must have escaped en route from Springfield. I bought a little knurled brass nut at the hardware store and epoxied it in place, no problem.
FWIW they must have really stockpiled a bunch of those UM boot grips, because they've been discontinued for quite a while and S&W still has them lfor sale at $22 delivered.