Cartridge : 5.45x39mm Bulgarian 53gr boattail steel core FMJ Firearm : Romanian AK74 with 16.5" barrel length Block calibration : 9.5cm @ 578 ft/sec (no correction applied due to bullet tumbling) Single shot fired to the center of the block from 10 feet distance. Bullet impacted at 3014 ft/sec, penetrated to 2.5" and turned on its side. This sideways penetration continued until 8.8" depth, at which time the bullet apparently righted itself. This orientation continued until ~ 9.0" penetration depth, at which time the bullet again turned on its side and continued on in the sideways orientation until bullet exit at 16.0" depth. At this point, the bullet impacted the test stand upon which the block was sitting, and traveled an unknown distance into the polyester bullet arresting box. Bullet was recovered undeformed at 52.9gr.