Which Caliber is best for Defensive Shooting?

The caliber best suited to defensive shooting is an argument that is fought passionately by proponents of many calibers. Because of the emotion involved this is an argument that is impossible to settle. In an attempt to remain neutral and allow you to make an informed choice, let’s first consider the purpose of our defensive firearm.

The purpose of our Defensive Firearm is simple. STOP The Threat. That is it, nothing else. So how does a Firearm stop the threat? Well there are several, let’s look at them.

1. The simple sight of our firearm may cause an attacker to desist.
2. Simply being shot even if a minor wound from a small caliber firearm can cause a shock reaction which may cause an attacker to desist.
3. Skeletal Damage. Breaking bones especially pelvic, spinal or thigh bones can render an attacker immobile and allow us to escape.
4. Vascular Damage. Loss of 50% or more of the blood supply is usually fatal. However it takes time to bleed out and even a heart shot may not stop an attacker for several seconds.
5. Pulmonary System. Hits to the Lungs, Trachea or Diaphragm reducing the ability of an attacker to breath. While these can prove fatal they may take several minutes to disable an attacker.
6. Central Nervous System. Hits to the Brain or Brainstem are almost always instantly disabling if not fatal, while hits to the spine cause various degrees of disability.

Obviously the Central Nervous System is our best stopping shot and almost any caliber can cause instant incapacitation if placed correctly. Unfortunately the head is a difficult target to hit due to its small size, the thickness and curvature of the skull and the fact that it is almost always in motion. Your target zone is about a 4’ X 2’ letter box. Also the Brainstem and Spine are all well protected on the back side of our target and only about 1” wide. It is important to remember that you are responsible for all the rounds you fire and a miss on a head shot is going somewhere.

Our best chance of hitting our target lies in having a bigger target that offers us a good probability of stopping the threat. Torso shots offer us an excellent chance of Vascular, Pulmonary damage with a small chance of a Central Nervous System (spinal) Damage and a good chance of inducing Shock. However multiple shots may well be required to stop our threat.

Bearing in mind that we will only be 50% as good in a Defensive Encounter than we were in training. The center mass shot with multiple quick follow up shots makes sense. Remember we shoot till the threat stops. We should be practicing placing multiple shots on target.

So what does our bullet need to do to stop the threat?

1. Penetrate Clothing, Skin, Fat and Muscle to reach the Vital Organs.
2. Have sufficient Energy to expand and create maximum damage.
3. Stop inside the target using all its energy and not pass through and do unintended damage.

As we cannot accurately predict the size of our assailant, they may be 100lb dripping wet or a 350lb NFL linebacker we should assume we need at least 6” of penetration and a maximum of 17” of penetration. We also need sufficient energy to ensure bullet expansion to create maximum damage.

There are numerous websites with penetration tests and ballistic gel tests that are easily found online so I will not go into the factual numbers for all the different bullet weights and powder loads. Suffice to say that for a center mass shot the calibers that meet the above requirements for penetration and energy for expansion are between .38 and .357 mag for pistols.

Yes, I hear you say you left out the 10mm and it is an effective round however Federal agencies dropped it because of over penetration. Yes I hear that I did not include hydrostatic shock. Hydrostatic shock is a minimal effect with pistol rounds as it does not really come into play till rounds are traveling at supersonic speeds. I will not gross people out with actual photos but the difference between the damage caused by a high velocity pistol round and a high velocity rifle round is like the difference between a hand grenade and a 1000lb bomb.

So what do I use? Well I use a 9mm because I can accurately place rounds center mass quickly. I shoot 45 well on the range but I am more accurate and faster with a 9mm. At the end of the day it comes down to what you can accurately and quickly place multiple rounds on target. Only Hits Count in a Defensive Encounter.