High Velocity Underwood .40 S&W vs Heavy Steel Door - TheFireArmGuy
This video tests the penetration capabilities of high-velocity .40 S&W ammunition, specifically Liberty Civil Defense and Underwood, against a heavy steel door. Both brands, utilizing lighter, high-velocity hollow-point bullets, successfully penetrated the door, which had previously stopped standard full metal jacket and hollow-point rounds. The Underwood ammunition showed more expansion upon impact.











