I've got a .357 649 and I always shoot .357 in it. After a few thousand rounds it has no endshake or timing problems. Your hand will wear out first. It's probably not as durable as a Ruger SP101 but I doubt that I'll wear it out anytime soon.
All you have to do is take a look around and see the thousands and thousands of old beater ones still out there going strong to know they can stand up to the test of time.
I honestly don't shoot much .357mag out of mine though. I find .357mags to be extremely unpleasant out of small revolvers.
I have shot a fair amount of .357 out of my 3" M60 with no ill effects on the revolver. Ill effects on me is a different matter. A diet of .357 out of doggone any J-frame is not a pleasant proposition to me. Holster choice? Here is a pic of my M60 in a holster by Simply Rugged which is a really well made piece.
My Model 60's are earlier ones that I bought around '80 (one each for both my wife and me). They're both "no dash" as far as I can see, and they are stamped for .38 Special, not .357.
I wouldn't care if they were .357 because I wouldn't fire them or carry them with anything but .38 Spec. anyway.