You know you have to much when you run out of space and have to stack it around the toilet such that it and the ammo falls through the second floor on to the first floor.
A friend of mine swears this happened to someone he knows. I do know someone who was sitting on the can - no ammo around him - and the throne plunged through the second floor to the first. He was seriously injured.
So I supposed ammo could accelerate the process.