Stock cracks....not always but most often are a result of loose screws and heavy loads. Always make sure the screws are tight (not Neanderthal tight) and you shoot a low pressure light load and most guns will hold up fine. These two actions increase the odds of not uaving a stock problem. What you do not know with any used gun is what kind of care it had before you. You cannot fix that. Inspect it carefully. Glass reinforcing is an option to also decrease the likelihood of problems. Even with this I don't shoot over 1oz 1200 fps out of my guns.