SIG Sauer P320-M18X RX 9mm Compact, Coyote PVD, 3.9 in Barrel, ROMEO-M17 Red Dot, 3x 21-Round Mags
The SIG Sauer P320-M18X is a compact, X-Series variant of the M18 pattern with a 3.9 in slide, coyote PVD finish, and factory-installed ROMEO-M17 enclosed-emitter red dot. It pairs the modular P320 FCU with an X-Series Carry grip module and flared magwell, and comes with three 21-round magazines. Commercial M18X models were introduced in late 2023.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are a few blemishes and areas of handling wear concentrated on the front portion of the slide. The bore is bright, clean, and well maintained.
What’s Included
- SIG Sauer factory hard case
- Manual
- SIG Sauer ROMEO-M17 enclosed-emitter red dot sight (installed)
- Three 21-round extended steel P320 magazines with coyote polymer baseplates
The P320-M18X follows the M18-length format with a 3.9 in barrel and slide and features M18 slide marking. Its coyote PVD-coated stainless slide and coyote polymer frame present a consistent duty-style finish. The frame is marked NEWINGTON, NH, USA.
As an X-Series, this pistol uses the modular P320 Fire Control Unit architecture and an X-Series Carry grip module with a flared magwell for confident reloads. Controls include an ambidextrous slide catch and ambidextrous manual thumb safety.
The striker-fired system uses a flat-faced trigger and incorporates internal striker safety. A 3-slot accessory rail on the dustcover supports weapon-mounted lights or other rail-compatible accessories.
Factory sights include a front night sight, while the rear sight position is occupied by the optic body. The ROMEO-M17 is an enclosed-emitter red dot using the SIG-LOC mounting interface with a sealed, gas-purged 7075 aluminum housing. Romeo-M17 Red Dot Optic installed.
Capacity is 21+1 rounds, and this example includes three 21-round extended magazines with coyote baseplates to match the pistol’s finish, aligning with the compact slide and X-Series ergonomics.