Every day at the downtown Ottawa police headquarters, a gun is fired. Any firearm seized by police is tested with a ballistics tank at its indoor range. It's a stainless steel secure box filled with water, to slow down the projectile. Whether the gun is confiscated from a gangster or for another reason, police always need to shoot the gun as part of their investigation. Besides determining whether the gun is in working order, its projectiles collected from the tank... (GunPolicy.org)