Tom,
Knew a guy who had to send his 19 back for rebuilds twice, after which S&W said "Last time, no mo."
It's partly those lightweight bullets, but there can also be frame stretching, cone erosion, cone cracking & so on.
I said CAN be, no flames on the durability of the 19, please.
Good guns, genuine classics, just not built for HEAVY use of full-bore .357s.
Denis