JP SCS Auxiliary Spring Rate Kit For 9mm SCS

The Auxiliary Spring Rate Kit for the JP Silent Captured Spring allows custom tuning of the device to a given rifle. While the default spring installed in the JPSCS is selected to offer the best performance for the widest range of configurations, a simple disassembly and reassembly of the JPSCS with a slightly different spring rate can yield truly optimized performance. In selecting a spring for your rifle, install a heavier spring if you feel the buffer head fully compress and bottom out while firing the weapon. If the bolt will not lock back reliably on the last round fired, select a lighter spring. The included springs from lightest to heaviest are listed below with the color with which they are coded: JPSCS-SPRING15-100: Uncolored JPSCS-SPRING10-100: 1 side red and 1 side uncolored JPSCS-SPRING10-110: 1 side yellow and 1 side red One spare guide rod retainer screw is also included in case of thread stripping during disassembly.