Cartridge : Federal 3" magnum # 2 buckshot (produced 12/1974) Firearm : Recoil operated shotgun with 26" barrel length (2 3/4" chamber) Calibration : 11.2cm at 586 ft/sec NOTE : This particular round is over thirty years old and was a 3" shell fired by sheer negligence, by the brassfetcher, in a 2 3/4" chamber. Do not imitate this to get these ballistics - it's not worth the risk. Firing this round in a 3" chamber with identical barrel length will yield this type of result. Single shot fired at 10' distance from the block. 1137 ft/sec impact velocity. Average penetration was 13.6" with the deepest penetration occuring at 14.8" and the shallowest penetration at 11.1". The balls all had sharp flat spots on them - likely due to impact with the wall of the chamber.