While Smiths can and do crack, so do boxlock guns such as Parker and Fox. You just can't see them until you take the action off. The top tang pin and hand pin in a Smith are more of a recoil lug than most people realize. How many low grade Parkers have you seen with the flats behind the action checkered to hide the cross pins used in the repair. Or wood putty over the ends of the "stove bolt" used to hold the stock together. Fox used a piece of metal driven into the head of the stock to help prevent splitting. As for the OP shoot light loads in your gun as much as you want. If it develops issues with the stock fix them and carry on. When components become available again star reloading 3/4 oz loads. That load will break trap targets out to the 22=23 yard line with no problem. A 20 ga Smith gun is a joy to carry and will go on shooting for your lifetime with a bit of care and judicious thought to you loads. ENJOY it
