1st off the wood will not "blow up" in you face. Worse case scenario is the stock catastrophically fails the receiver and it will separate and if you don't catch it one or both pieces will fall to the ground. Would I shoot it as it? Yes but only limited. Depending on what the gun is getting it fixed or at least staking the crack, replacing the stock or wrapping in Gorilla tape are all options. Anything is better than nothing.
A word on buck shot and/or high brass shells. The powder charge/type and wad used are what create recoil. A once of lead or an once of feathers is still an ounce. High brass shells are a throw back from the time when shells were loaded with black powder. Since more powerful shell take more powder the brass has to be higher to keep from burning through the paper hull. With modern plastic shells and smokeless powder I can reload a shell hotter than any "high brass" with no ill effect. But people like to see high brass shells thinking they are more powerful when in reality you need to read the box and get the info off it like FPS, and shot capacity.