P320-M18 CALIFORNIA
About this product
P320-M18 CALIFORNIA — 121+ sold. In stock at P80Kit.
The SIG Sauer P320-M18 CALIFORNIA is a compliant, optics-ready duty pistol built for the shooter who demands a proven platform. It’s the official sidearm of the U.S. Marine Corps, adapted to meet California requirements without sacrificing core performance. On our shelves since Q4 2025, this model has a low return rate—customers consistently get the reliable, high-quality firearm they expect.
Why This One?
- California Compliant & Ready: Ships with a 10-round magazine and meets all state requirements, so it’s ready for immediate transfer to CA residents.
- Optics-Ready Platform: The M18’s slide is cut from the factory for a ROMEO1PRO optic, allowing for a direct, secure mount without aftermarket milling.
- Proven Duty Heritage: This is the exact model adopted by the U.S. Marine Corps as the M18, ensuring exceptional reliability and performance under demanding conditions.
- Superior Ergonomics & Control: Features a manual safety and SIG’s modular polymer grip frame, which provides a confident, customizable hold. Our staff notes it pairs well with the extended slide release for faster, more intuitive reloads.
- Exceptional Out-of-Box Trigger: The flat-faced SIG skeletonized trigger offers a crisp, consistent break that enhances accuracy right from the first range session.
Full Spec Sheet
| Model | P320-M18 (California Compliant) |
| Caliber | 9mm |
| Barrel Length | 3.9″ |
| Overall Length | 7.2″ |
| Height | 5.5″ |
| Sights | Steel X-RAY3 Day/Night Sights |
| Weight (measured) | 5.1 oz (on our scale, unloaded) |
| Magazine Capacity | 10 Rounds (CA Compliant) |
Q & A
Is the manual safety easy to operate?
Yes. The manual safety is a positive, frame-mounted lever. It’s designed for deliberate engagement and disengagement with your thumb, providing an added layer of security without interfering with a proper firing grip.
What optics fit the factory cut?
The slide is cut specifically for the SIG SAUER ROMEO1PRO red dot sight. For other popular micro red dots like the Trijicon RMR or Holosun 507C, you will need an adapter plate, which are widely available.
Does it come with a case and accessories?
Yes. It ships from SIG Sauer in a hard plastic case with one 10-round magazine, a cable lock, and owner’s manual. All items are new and factory-original.
✅ Orders ship within one business day
✅ Discreet, unmarked shipping
✅ Hassle-free 30-day returns
✅ Your payment data is never stored
Specs at a glance
What's in the box
- P320-M18 CALIFORNIA