SIG Sauer P320

The SIG Sauer P320 is a semi-automatic pistol made by J.P. Sauer & Sohn, and SIG Sauer of Exeter, New Hampshire. The SIG Sauer P320 can be chambered in .357 SIG, .40 S&W, .45 ACP, and 9×19mm. The P320 chambered in 9×19mm was introduced in the North American market on January 15, 2014 followed by the .45 ACP compact model at the SHOT Show in January 2015. The P320 is a further development of the P250 utilizing a striker-fired mechanism in lieu of a double action only hammer system

Operating mechanism
Like other SIG Sauer pistols, the P320 pistol is a short recoil operated, locked breech pistol. It uses the typical SIG Sauer cam-operated barrel, which locks into the ejection port on the slide.

Features
A key feature of the pistol is its modular design. The main module of the P320 is an internal stainless steel frame fire control unit which consist of the integrated fire control group (trigger, hammer and all necessary linkage and springs), ambidextrous slide release (one on each side of the pistol), ejector and four slide rails. This steel receiver unit is used in every P320 grip module, top end, and chambering combination and is inserted into the grip frame module and held in place by the axis pin of the disassembly lever. The firearm's serial number is on the fire control unit instead of the grip module. The fire control unit allows the operator to interchange differently-sized slide assembly or top end modules and polymer grip frame modules and trigger shoes and (limited) chambering conversions to adapt the gun to the individual user and address different needs.

The P320 was designed to be ambidextrous in handling, sporting an ambidextrous slide catch lever and user reversible magazine catch. All other operating controls are designed so they can be operated from either side. The firearm can be field stripped with no tools. Additionally, the firearm can also be field stripped without depressing the trigger or requiring a tool, an additional safety feature to prevent negligent discharge of the weapon.

The full-size, carry and compact grip modules feature an integral Picatinny rail mounting-bracket at the lower forward edge of the module to allow the mounting of laser sights, tactical lights, and other accessories.

Modular options


The P320 pistol is offered in three glass-reinforced polymer grip module sizes—small, medium, and large — in each of the full-sized, carry/compact, and subcompact P320 variants. The pistol top ends also come in full-sized, compact, and subcompact variants that will fit the correspondingly sized grip modules. Every chambering can be converted by the user with a caliber exchange kit. The 9×19mm Parabellum, .40 S&W, and .357 SIG chamberings share their polymer grip frame modules and this offers the possibility to interchange these three chamberings by swapping the top end — consisting of the slide, recoil spring assembly, barrel and the box magazine. Due to the significantly larger external dimensions of the .45 ACP cartridge compared to the other P320 chambering options, the .45 ACP chambering uses slightly wider .45 ACP specific polymer grip modules with an enlarged magazine well.

The manufacturer offers caliber exchange kits or Caliber X-Change kits consisting of a slide, recoil assembly, barrel, box magazine and grip module in the varying frame sizes, grip module sizes and chambering variants in which the P320 pistol is offered. These kits enable a user to switch between the various P320 configurations without the use of tools.

Safety
The P320 has no manual safeties to promote instant readiness. Instead of manual safeties an automated firing pin safety ensures safe carrying of the weapon whilst preventing accidental discharges if the gun is dropped or roughly handled.

Trigger system
The trigger is a self-cocking DAO trigger system with a spring powered striker. The trigger system has a pull weight of about 28.95 N, 5.5 lbf

The P320 trigger is available in standard (solid) and tabbed (with trigger safety)

Barrel
The P320 is available with a 120 mm, 98 mm, or 91 mm barrel depending on the size (full-sized, carry/compact or sub-compact respectively).

Ammunition feeding
The pistol feeds from metal detachable box magazines with a six- to seventeen-round magazine capacity, depending on chambering and pistol size.

Sights
The P320 comes with three-dot combat-type iron sights of which the front sight element can be drifted to the left or right in its dovetail to adjust for windage. There are three rear sight heights and six front sight heights available to adjust for elevation. Self-luminous tritium powered SIGLITE Night Sights in differing heights are optional. SIGLITE night sights are optional, but come standard in exchange kits.

Accessories
The factory accessories consist of spare magazines, caliber exchange kits, a short reduced reach trigger shoe, handgun holsters, and the STL-900L Tactical Light/Laser unit.

Variants

 * Modular Handgun System Variant - Designed to meet the requirements for the MHS program. Modifications include:
 * Ambidextrous thumb safety
 * Loaded chamber indicator
 * Improved slide sub-assembly to capture small components when disassembled
 * Improved trigger "mud flap" to prevent foreign debris from entering the pistol action

Reviews
Rob Curtis at GearScout praised the P320's smooth operation and good balance, calling it "immensely controllable", but noted a problem with the slide lock in both test units he tried.

Users

 * 🇹🇭 Thailand: Request for permission for duty-free private purchases by members of the Royal Thai Police; 150,000 batches
 * 🇺🇸 United States:
 * University of Cincinnati police.
 * Union Beach Police. Union Beach, New Jersey
 * Texas Department of Public Safety, Texas Highway Patrol
 * Hookset Police. Hookest, New Hampshire
 * High Point Police. High Point, North Carolina
 * Hawaii Department of Public Safety. Hawaii
 * Oklahoma Highway Patrol