The characteristics of the most powerful handgun are constantly evolving as gun designers tinker with new cartridges and develop more powerful loads. Power in the context of small arms typically refers to kinetic energy, half the projectile’s mass times the velocity squared. This is the energy that an object has when in motion, directly affecting the damage a projectile causes to its target.
If you select a handgun for self-defense or hunting, muzzle energy is not the only factor you should consider when assessing its power. The cost and availability of the ammunition, recoil and controllability, magazine capacity, practical accuracy, size, and weight of the firearm all contribute to the level of power a handgun offers.