The . 45 caliber MAC 10 weighs 6.26 pounds when empty and it fires 1,145 rounds per minute. The maximum effective firing range is 50 meters and the muzzle velocity is 280 feet per second. ... 380 caliber MAC 11 weighs only 3.5 pounds, fires 1,200 rounds per minute and has a muzzle velocity of 980 feet per second.