Ramset .22 Caliber Trigger Shot Tool. Use the trigger shot tool for fastening to concrete, masonry and steel. The trigger shot is easy to use and great for wall applications and between studs. The positive barrel and load retention will prevent the barrel from opening freely, allowing for easy overhead and horizontal fastening. The tool uses the .22 caliber Ramset loads. After each use the power load will automatically eject, allowing you to quickly complete your jobs.