Sig Sauer P320 Cal-X P320-M18 9mm Carry Coyote (1)17rd & (2)21rd Mags X-Change Kit CALX-M18-CSS-MS

The SIG Sauer Caliber X‑Change Kit — P320 → M18 (CALX‑M18‑CSS‑MS) is an OEM, drop‑in conversion kit that transforms a compatible P320 fire‑control unit into the commercial M18 carry configuration. Finished in factory coyote PVD, the kit includes a 3.9″ M18 slide assembly (optics‑ready to the MHS/ROMEO‑M17 footprint), 3.9″ barrel and recoil assembly, a coyote carry grip module with manual safety, and three magazines (one 17‑round and two 21‑round). It ships with SIGLITE night front sight and a removable night‑sight rear plate for easy red‑dot mounting — delivering military styling, optics capability, and extended magazine capacity without gunsmithing. Confirm your P320 FCU is the correct caliber and safety configuration before installing this kit. Sig Sauer P320 Cal-X P320-M18 9mm Carry Coyote (1)17rd & (2)21rd Mags X-Change Kit CALX-M18-CSS-MS