SIG Sauer P320 Nitron Sub-Compact 9mm, Striker-Fired, Modular FCU, 3.6" Barrel, 21+1 Capacity
The P320 Nitron Sub-Compact is the smallest factory form of SIG’s popular striker-fired series. Its serialized stainless-steel fire-control unit (FCU) allows full modularity, while the 3.6-inch barrel and shortened grip make it easy to conceal without giving up capacity. This early-generation example, marked “NEWINGTON, NH,” comes with seven factory magazines ranging from 12 to 21 rounds, letting you tailor size and firepower to the task.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
What’s Included
- SIG SAUER factory hard case
- SIG SAUER P320 owner's manual
- 3 factory 21-round steel magazines (Made in Italy) with detachable grip-fill sleeves
- 1 factory 17-round steel magazine
- 3 factory 12-round steel magazines
- Detachable polymer magazine sleeve adapters
- Small spare part in sealed plastic bag (unidentified)
This sub-compact P320 keeps the proven striker-fired action but trims overall length and height for carry. The Nitron-finished stainless slide offers forward and rear cocking serrations for confident manipulation, while the polymer frame incorporates molded rails for accessories.
The heart of the design is SIG’s removable stainless FCU. Because the FCU is the serialized component, the user can swap frames, slides, and barrels to re-configure the pistol without new paperwork, creating unmatched modularity in a concealed-carry footprint.
Despite its reduced size, the pistol feeds from full-capacity P320 magazines. The included 21-rounders extend below the grip and use sleeve adapters to maintain a solid hold, giving you duty-sized capacity when desired. Three flush 12-round magazines keep the profile minimal for everyday carry.
A curved, serrated trigger pairs with multiple passive safeties—striker safety and disconnect safety—to deliver a consistent pull with no external levers to deactivate. Traditional 3-dot iron sights arrive dovetailed front and rear for easy replacement or drift adjustment.
Built in SIG’s Newington, New Hampshire facility, this P320 Nitron Sub-Compact combines American manufacturing with the company’s modular striker-fired architecture, offering a versatile package ready for range, defense, or discrete carry.