HANDGUN ENERGY

How Powerful Is Your Ammunition

The velocity numbers used in this spreadsheet were obtained from: www.ballisticsbytheinch.com

I have used the muzzle energy calculations from the Wikipedia page: http://en.wikipedia.org/wiki/Muzzle_energy where they explain:

Muzzle energy is the kinetic energy of a bullet as it is expelled from the muzzle of a firearm.

It is often used as a rough indication of the destructive potential of a given firearm or load.

The heavier the bullet and the faster it moves, the higher its muzzle energy and the more damage it will do.

The general formula for the kinetic energy is

Where:

v is the speed of the bullet and

m is the mass of the bullet.

Care must be taken when using this formula that consistent units are used.

In SI units:

If the mass, m, is in kilograms and the speed, v, is in metres per second, the calculated muzzle

energy, E_k, will be in joules.

If the mass, m, is in grams and the speed, v, is in kilometres per second, the calculated muzzle

energy, E_k, will be in kilojoules.

In American engineering units: 

Mass, m, is usually given in grains and the speed, v, in feet per second but kinetic energy, E_k, is

typically given in foot-pound force.

Most sporting arms publications within the United States report muzzle energies in foot-pound

force.

These units are not self-consistent thus a conversion factor must be added.

The above formula thus becomes:

When publishing kinetic energy tables for small arms ammunition, an acceleration due to gravity of 32.163 ft/s2 rather than the standard of 32.1739 ft/s2 is used. The formula therefore becomes:

This is the formula that I use in my calculations:

The final number is in foot-pounds of force.

For convenient comparison, the table below depicts the most powerful results for each worksheet in this document.

HERE is a link to the raw spreadsheet data.

Things I find interesting:

Something as small as a 1 inch change in barrel length can make a difference of 100 - 150 foot-pounds of force.

 

Sometimes a smaller bullet has more force than a larger one because it is travelling faster.

(As an aside, they say you want the fastest bullet possible because of the hydrostatic shock effect of the high speed bullet.)

 

A 4-inch .40 S&W with the right ammo can be more powerful than a 4-inch .45 GAP and is almost as powerful as a 4-inch .45 ACP and a 5-inch .45 GAP.

 

Ammunition that may be identical in caliber and weight, and being shot from the same firearm may vary up to 100 foot pounds of force depending on the manufacturer of the ammunition.

Remember Isaac Newton: For every action, there is an equal and opposite re-action. The more powerful the force of the bullet as it leaves the gun, the equally more powerful is the recoil.

Be sure to select the most powerful ammunition you can shoot comfortably, consistently and accurately. It does no good if you can't hit your target because the ammunition is too powerful for you to control properly.