Hell, I had one that was literally bullet proof. We used it as a stand to put things on that we shot, and everything from .22 to 9mm would - at best - pass through one side then rattle around inside. .45 would pass all the way through more often than not, and rifle rounds would pass completely through as well. But for small-caliber pistol rounds, this chassis (a full-tower server chassis,) would have been a perfectly decent thing to duck behind if a firefight broke out. That chassis was our "shooting target stand" for a couple years before it finally sustained enough structural damage to no longer be useful.
And yes, I had used it as a step-stool before. It was sturdier than many real step-stools I have used before. It had zero problems holding my 200-lb. self, including jumping on it.