Metal Storm Weapons: Million-Plus Rounds Per Minute
ODwyer constructed a triple-barrel, a nine-barrel, and a 36-barrel firing prototype design that he lovingly named Bertha. The reason for the 36 barrels was simply to indicate to ourselves and to others the future versatility of this system, in that with the 36 barrels we had 540 rounds on board and, based on the 45,000-round-per-minute rate per barrel, that gave us a maximum firing rate of 1.62 million rounds per minute, the inventor says