I was shooting this with 357 rounds and all of a sudden the trigger got hard to pull...inspecting it further the cylinder doesn't freely lock into position.it binds.. Any thoughts would this be something S&W would repair?

Sounds like the extractor rod has come unscrewed and is binding on the frame. Check and see if the knob on the end has backed out but be careful, I think it's a left hand thread.

It may be something as simple as a few unburned powder granules
under the ejector star thats causing the cylinder to drag on the frame.
Check and clean if needed.

I also vote for the loose extractor rod - been there done that. And yes, it is a left hand thread. If you need some step-by step instructions on how to tighten it up, send me a PM. I recently had to do this to my 15-5 to swap the cylinder. Not too hard.

Sure sign the gun has come to the end of its useful life.

But if you send it to me I can probably salvage the grips and dispose of it properly.

Seriously--sounds like the above advice will have you on the road again in no time.

I tried the extractor rod and the star extractor no luck the rod was tight and clean as a whistle under the the extractor. one friend said crane??

If you're shooting lead bullet ammo you could have some lead fouling
build up on the front face of the cylinder or rear face of the barrel
causing the cyl to rub against the barrel. Look for rotation scrapes on
the cyl as evidence of binding. Check the firing pin bushing to see if it
might have backed out of it's hole in the frame causing a bind. If you
bought it used it might have a bent ejector rod or sprung crane from
abuse of a previous owner. Check the cyl retaining screw in the
sideplate, the front one. Too tight or too loose or ill fitting can cause
problems with the cyl crane.