Bunny Workshop reviews the KSC Vz61 Heavyweight GBB Machine Pistol. The KSC version is the System 7 Japan version which can be fired in semi and full automatic modes. The body is made of Polymet with fixed front and rear sigths. The over folding stock is made of steel. It fires fast though with the standard 20 round magazine, you would go through it quickly. But there is a long version of the gas magazine. Price of this GBB at Bunny Workshop is US$275.00.