Bullet Caliber and Penetration Levels

Understanding how each bullet caliber has different penetration levels is essential for deciding what level of bulletproofing protection you want to achieve.

Engineering Center - Design to Protect

Handgun Bullet Size Chart - What Sizes Do Bullets Come In?

IS LEVEL IV UNBEATABLE? Armor, Caliber, and the Problem with Tungsten -The Firearm Blog

8 Best Calibers For Self Defense

FBI Training Division Justifies 9mm Caliber Selection -The Firearm Blog

Projectile Performance for .50-Cal. Pistol Bullets

Pocket Pistol Caliber Ballistic Gel Tests - Labs

Will a 5.56 green tip penetrate body armor? - Quora

45 ACP - Wikipedia