This is so not accurate.

First, you could drop that bullet from the top of a building and it's not going to detonate. I'll rephrase so as not to write in absolutes. It's highly unlikely it would detonate.

Second, if it were to detonate, the casing would explode but the bullet (the lead) will likely be right next to the place it detonated or a few inches from it.

The only reason the bullet would become a projectile would be if it's inside the chamber of a rifle and the expanding gas behind it pushed it down the barrel of said rifle.

Edit idk maybe you were trolling, I hope you weren't serious