SIG Sauer P320


The SIG Sauer P320 is a modular semi-automatic pistol made by SIG Sauer, Inc. of Exeter, New Hampshire, and SIG Sauer GmbH of Eckernförde, Germany. It is a further development of the SIG Sauer P250, utilizing a striker-fired mechanism in lieu of a double action only hammer system. The P320 can be chambered in 9×19mm Parabellum,.357 SIG,.40 S&W, and.45 ACP, and can be easily converted from one caliber to another—a change from.357 SIG to.40 S&W requires only a barrel change; a change between 9mm to.357 SIG or.40 S&W and vice versa are accomplished using a caliber exchange kit.
The P320 chambered in 9×19mm Parabellum was introduced in the North American market on 15 January 2014, followed by the.45 ACP compact model at the SHOT Show in January 2015. On 19 January 2017, it was announced that a customized version of the SIG Sauer P320 had won the United States Army's XM17 Modular Handgun System competition. The full-sized model will be known as the M17 and the carry-sized model will be known as the M18.

Design details

Features

The P320 was designed to be ambidextrous in handling, sporting a catch lever on both sides of the slide and user-reversible magazine release, and 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, an additional safety feature to prevent negligent discharge of the weapon.

Trigger system

The P320 trigger is available in standard and tabbed.

M17 and M18

When the requirements were formulated for a new handgun for the US Army one of the tenets of the proposal was that an existing model handgun was desired to fulfill the requirements laid out in the Modular Handgun System Request for Proposal, known as the XM17 Procurement. SIG Sauer submitted a P320 with a number of modifications and submitted them for the XM17 Modular Handgun System competition.
Modifications include:
On 19 January 2017, it was announced that the SIG Sauer P320 MHS variant had won the United States Military's Modular Handgun System trials. The P320 will be known as the M17 and M18 in U.S. Military service. Though the pistol will remain chambered in 9 x 19mm Parabellum rather than a larger caliber, the contract allows the services to procure SIG Sauer's proposed XM1152 Full Metal Jacket and XM1153 Special Purpose ammunition. The ammunition chosen to go with the pistol is a "Winchester jacketed hollow point" round.
In May 2017, the Army announced that the first unit that will receive the M17 would be the 101st Airborne Division by the end of the year. At the same time, the rest of the U.S. Armed Forces revealed they also intend to acquire the handgun, making it the standard sidearm for the entire U.S. military. The services plan to procure up to 421,000 weapons in total; 195,000 for the Army, 130,000 for the Air Force, 61,000 for the Navy, and 35,000 for the Marines.
On 17 November 2017, soldiers of the 101st Airborne received the first XM17 and XM18 pistols, with over 2,000 handguns delivered. The XM17 has better accuracy and ergonomics and tighter dispersion than the M9. It will also be fielded more widely, being issued down to squad and fireteam leaders; while special forces would dual-arm all of its members with a pistol and rifle, previously junior leaders in regular infantry units were excluded from carrying sidearms but policy was changed to give them more choices and options in close quarters battle situations. All Army units are planned to have the M9 replaced with the M17 within a decade.

Reliability

Initial production models of the P320 were noted to have a 'drop safety' issue if the firearm was dropped on a specific angle causing it to discharge. Sig has since refitted the P320 with a new trigger with reduced mass and a new striker disconnect that makes it drop safe. Sig also offers a voluntary exchange program to fix any defective P320s.
Apart from initial teething issues, the P320 has proven itself to be an extremely reliable pistol for civilian, law enforcement and military use. Many police departments in the US and around the world have started issuing their officers P320s.

X Series Models

The X Series lineup includes the following grip module sizes:
In January 2019, SIG Sauer announced the XCompact handgun as the newest entry in their X Series lineup.
The XCompact size grip module is the smallest grip module SIG currently carries, as they have not come out with a subcompact X Series grip module to date.

XFive Legion

Release in late July/early August of 2019 the XFIVE Legion is considered the flagship of the P320 platform that brings a balance of added weight and features. The TXG grip module has tungsten infused directly into the polymer along with an attachable magazine well. It comes standard with Henning group aluminum base pads and a skeletonized flat trigger. The complete 9mm slide is cut and ported to reduce weight and assist in recoil and feeding abilities. It also has a slide plate for optic capabilities.

Drop firing problem

In late July 2017, the Dallas Police Department in Texas instructed all personnel to stop carrying the P320 pending an investigation. There were concerns that the firearm may discharge when it is dropped and the back of the slide hits the ground at a 33-degree angle. The problem was thought to be related to the trigger weight; some triggers were heavy enough that they essentially continued to move due to inertia after the gun hit the ground. Internet publications, such as TheTruthAboutGuns.com, conducted independent tests that appeared to confirm potential drop firings.
On 8 August 2017, SIG Sauer issued a notice that they would upgrade all P320s to address the issue. The upgrade is described on the company's website as: "This will include an alternate design that reduces the physical weight of the trigger, sear, and striker while additionally adding a mechanical disconnector." The P320 upgrade program is detailed on the SIG Sauer website at: .

Lawsuits

''Steyr Arms, Inc. v. Sig Sauer, Inc.''

In May 2017, Steyr Mannlicher filed a patent infringement lawsuit against SIG Sauer. Steyr refers to their patent US6260301, which is for a handgun with a removable chassis. Steyr Arms requested a preliminary and permanent injunction against SIG Sauer selling any such firearms. On March 11, 2020, the United States District Court for the District of New Hampshire found that SIG Sauer did not infringe Steyr’s patents, and dismissed all motions.

''David Hartley, et al. v. Sig Sauer, Inc.''

A lawsuit related to the above noted drop firing problem and filed in April 2018 in the United States District Court for the Western District of Missouri led to a class action settlement in February 2020. Elements of the agreement include:
A class action settlement form is available on the SIG Sauer website.

''Derick Ortiz v. Sig Sauer, Inc.''

In September 2019, an Arizona gun owner who purchased a P320 in September 2016 initiated a class action lawsuit. It claims that SIG Sauer "continued to sell the flawed gun to the public", and that the upgrade offered "would still not fully compensate him for the significantly diminished resale value of his pistol." In March 2020, judge Joseph N. Laplante denied SIG Sauer's motion to dismiss the case.

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