About once a week I am asked about ammo. Most people ask "which is the best self defense ammo" or "which bullet has the best penetration." This is a loaded questions. No pun intended. Let's be honest, getting hit with any bullet is always potentially lethal. In any case, I'll take some time to talk about various factors that affect penetration and the effectiveness of self defense ammo.

99% of self defense ammo is sold using a hollow point (HP) bullet. The idea of the HP is simple, it expands once it hits something thereby creating a larger wound cavity. Larger wound cavity = more bleeding. Most gunshot victims do no die from lethal hits to the CNS. They die because they bleed out before getting the hospital.

Penetration is often incorrectly associated with self defense ammo. As I stated above, a hollow point expands and sometimes breaks into pieces depending on the design which effectively decreases penetration. A standard bullet (ball ammo) does not expand and will retain the classic bullet shape until it hits something very hard like steel or bone that will eventually deform the bullet.

So while ball ammo will penetrate more effectively than a HP, it won't open a large wound cavity like modern self defense ammo.


The reason HP ammo is used for self defense is two fold:

• Creating large wound cavities
• To prevent bullet exit

I already covered the wound cavity theory. Over-penetration which referrers to bullets that enter the then exit the body present two main problems. First, it may hit other people or objects behind the original target. Second, if the bullets passes through a human body with too little resistance, it lacks effective "stopping power."

Smaller calibers like .22, and .380 aren't associated with stopping power because the bullet weights are simply too light. The classic example of stopping power is the .45 ACP which travels relatively slow but has considerable mass. Personally, I always choose the heaviest HP bullet I can find for my own self defense loads. Be it 147 grain 9mm HPs or 230 grain .45 HPs you get the best of both worlds: large wound cavities AND stopping power.