Place a human in front of a wall, shoot in torso with EBR (7.62mm), check wall for impact mark. Place two humans behind each other, shoot in torso with EBR. Bullet fails to exit body.
Place human behind a brick wall, use the 12.7 HMG on the Hunter to shoot the wall, bullet does not exit wall.
Go to the car wreck in Agia Marina, shoot the rusty single door from the outside with 6.8mm or 7.62mm, check nearby wall for impact marks. Bullet does not penetrate car door.