Cartridge : .44 Magnum 240 grain Speer Gold Dot JHP (load # 23973) Firearm : .44 Magnum revolver with 4.0" barrel length. Calibration : 9.3 ± 0.05cm and 612 ± 0.500 ft/sec impact velocity. Single shot penetrated 16.0 ± 0.031" of gelatin block and ~8" of bullet arresting box. 1354 ± 0.500 ft/sec bullet impact velocity. Average recovered diameter was 0.730 ± 0.0005". Temporary cavitation from this round broke the wooden board that the block was sitting on, into two pieces lengthwise.