mancraft sdik cylinder srs tac41Mancraft's SDiK (Sniper Drop in Kit) which lets you convert a rifle with a spring system to gas, typically either Co2 or HPA The system is designed from the ground up and has gone through several generations and is patented, the entire system built around a reliable gas system. The SDiK is built to not wear on other parts of the rifle, meaning you don't need to upgrade either the trigger or cylinder to make it work. Once the system is installed, the