The story I've always heard was the K frames proved to have durability problems with 357 magnum cartridges.

This lead S&W to design the beefed up L frames like the 586/686.

But also, Smith has come out with J frames that have been upgraded to shoot 357 magnum.

So, are modern 357 magnum J frames more durable than K frames with the same diet?

Or should guns like the current production M60 not be shot much with 357?