The caliber of ammunition refers to the diameter of the bullet or projectile, and it plays a crucial role in determining the stopping power of the ammunition. Generally, a larger caliber bullet will have greater stopping power than a smaller one, but there are many factors to consider.

The weight of the bullet, the velocity at which it is traveling, and the design of the bullet can all affect the stopping power. A heavier bullet will typically have more kinetic energy upon impact, and a bullet that is traveling at a higher velocity will have more momentum. Additionally, bullets designed for expansion upon impact, such as hollow-point bullets, can cause more damage and increase the stopping power.

However, the effectiveness of a particular caliber of ammunition in stopping a threat depends on many variables, such as the type of target, shot placement, and the distance from the shooter to the target. Ultimately, the best way to determine the stopping power of a particular caliber of ammunition is through practical testing and evaluation.