I don't know about S&W magazines, but I spent a lot of years dropping Glock magazines on cement, gravel, grass, etc. Not one ever got damaged in any way, and between hubby and me, only one time did a base plate ever pop off and that was an after market one:
It happened at a gathering at a motel restaurant! Suddenly hubby got up from the table, holding his hip/back and headed for the bathroom. Fortunately he was wearing a sweater and was able to grab it in the right place to keep live rounds from "dripping out" on the way to the bathroom!