The MILSIG factory has had a break through in the design of their revolution Heat Core system. The NEW MILSIG Heat Core Upgrade Kit will fit EVERY MILSIG marker ever made.
The Heat Core system is an unbalanced spool valve design with a simplified blow forward operating system. Which makes it extremely stable and gives terrific shot to shot consistency. Infinitely easier to maintain and clean than the old blow back operating systems of all previous MILSIG markers. Maintaining the Heat Core and bolt requires the removal of only 2 quick strip pins.