Firearm : Gas-operated semi-automatic with 20.0" barrel length and 1/10" twist Cartridge : Handloaded 110gr Sierra Pro-Hunter soft-point Block calibration : All depths corrected (actual BB penetration was 13.0cm at 595 ft/sec) Single shot fired at 15 yards distance, impacted the block at 2466 ft/sec and penetrated to 12.5". Average recovered diameter was 0.551" and recovered weight was 77.0gr. Powder utilized was Reloader 10X (moderate load, but the gun owner/cartridge loader doesn't want the powder weight magnitude posted).