There are two LC Smiths. The regular frame stock is stronger than the featherweight. Back in the day they where made the ammo that was sold didn't recoil as sharply as todays shells. The feather weight stock is basically just four strips of wood up at the head with hardly nothing in between holding it together. Add 70 years,some oil, and modern trap loads or heavy hunting loads and the featherweight is notorious for cracking. There is no flat surface to transfer recoil from steel to wood. I'll bet Hunter Arms pushed the feather weight because it was cheaper to produce. When Marlin brought it back in the late 60's they advertised that the stock was glass bedded. That certainly helps but the design isn't that great.It may not be so bad in the smaller gauges but even a light 20g lets you know when it goes off.
