To better understand ballistic standards, it helps to understand muzzle velocity and muzzle energy. The chart below lists the muzzle energy (orange bars) of bullets fired by handguns and rifles ranked high-to-low. This mostly correlates with muzzle velocity of the bullet (blue bars) but not always. Because rifles have longer barrels, the expanding gasses from the exploding gunpowder have a longer/greater ability to accelerate the bullet. Thus, the bullets exiting a rifle’s muzzle are faster than bullets exiting a handgun/pistol’s muzzle. Since energy is calculated by the equation “half m v squared” or 0.5 times mass times velocity times velocity, increases in velocity have a large impact on energy. In the chart, energy is measured in foot pounds. Velocity, which is the speed of the bullet exiting the muzzle, is measured in feet per second. Mass is measured in grains (there are 437.5 grains in an ounce). The y-axis of the chart lists the types of bullet cartridges. H is for handgun, R is for rifle. The grains (weight) comes after the comma. To help put the chart into perspective, images of commonly recognized weapons are included. The ranges of protection afforded by BallistiGuard and BallistiMax are visualized on the right hand side of the graph. Visit our “Docs” page to see the relevant ballistic reports.