What happens if a smaller gauge shot shell is used in a larger gauge gun?

Using a smaller gauge shot shell in a larger gauge gun can lead to serious personal injury due to the potential for malfunctions and dangerous situations that may arise. When a smaller gauge shell is fired in a larger gauge chamber, it may not fit securely, which can cause the shell to become lodged in the barrel. This can result in a dangerous situation called a "squib load," where a projectile does not exit the barrel, followed by a subsequent shot that can cause the barrel to burst when the next shell is fired. The explosion of the gun can cause severe injuries to the shooter and bystanders, as well as damage to the firearm itself. Therefore, it is crucial to always use ammunition that matches the gauge of the gun to ensure safe operation and avoid accidents.