Penetration = 5.0 ± 0.031" due to breaking-up of projectile. All that was found after the shot was two small shards of lead and the entire volume up to 5.0 ± 0.031" filled with powdered lead. Impact velocity = 1782 ± 0.500 ft/sec Barrel was 18.0 ± 0.031" smoothbore with full choke Block calibrated at 575 ± 0.500 ft/sec and 8.7 ± 0.05cm penetration