SIG SAUER P320
INTRODUCTION Sig Sauer has a longstanding reputation for excellence in service handguns. The popular P220 series was at the head of the class when steel-framed double-action pistols were cutting-edge technology. The P226 was one of the most popular double-stack 9mm designs among both law enforcement and the civilian market. Before striker-fired pistols became all the rage, the Sigs and Berettas of the world were on top. Enter the Glock, with its striker-fired design featuring no exposed hammer, and a consistent shot-to-shot trigger pull that traditional double-/ single-action pistols could not replicate. The Glock offered a simplistic design, free of any manual safety except for the SafeAction trigger. It also had a polymer grip frame, making it much lighter than a comparably sized steel pistol. The Glock brought striker-fired designs to the forefront; with the P320, Sig sought to beat them at their own striker-fired game. ORIGINS OF P320 In the late 1990s, Sig attempted to enter the polymer pistol market with the Sig Pro line of pistols. The Pro line had the outward appearance of other Sigs, except it lacked a separate takedown lever and had an elongated slide stop. The SP 2340 Pro was introduced and was chambered in.40 S&W and.357 Sig. Next came the 9mm SP 2009, which was also a polymer, traditional double-action semi-auto. Later versions included compact models and a pistol with a traditional safety instead of a decocking lever. The current Pro line consists of the SP2022 full-size, and SPC 2022 compact pistols. Following the Pro series, Sig introduced the P250 pistol. The P250 double-action was the pistol that introduced the modular concept carried on into the P320. With one serialized fire control unit, the gun can be modified into a full-sized or compact unit in multiple calibers. Externally, the pistols are virtually identical, and are differentiated by the way their fire control mechanisms function. Both use a locked breech, short recoil operating system with a tilting barrel. STRIKER SYSTEM The P320 uses a striker system, similar to the Glock, Springfield XD, Smith & Wesson M&P, and other popular guns. Striker-fired pistols have hammer and firing pin combined, usually held to the rear under spring tension until the trigger is depressed. The P320 s striker does not lock fully to the rear; the trigger must be depressed to complete the cocking action. This unique system also allows the Sig to have an excellent trigger, with a very short reset compared to other striker-fired pistols. SAFETY The P320 was designed to be safe to operate and disassemble. There is a drop safety to prevent the gun from discharging unless the trigger is pulled and a disconnect safety to keep the gun from firing out of battery. A tabbed trigger and magazine disconnect are both optional. To further enhance safety, the Sig offers a unique disassembly sequence. While the Glock, Smith M&P, and similar designs require the trigger to be pulled in order to disassemble them, the P320 has eliminated this dangerous procedure.
ADAPTABILITY One of the most unique aspects of both the P250 and P320 is their ability to be converted to any size from subcompact to full. This is accomplished through the use of a removable steel fire control group, which is the serial numbered part of the pistol. This metal frame can be inserted into a full-size, carry, compact, or subcompact grip module. The modular trigger frame also allows 9mm,.357 Sig,.40 S&W, and.45 ACP to be fired from the same gun. There is a slide stop mounted on either side of the frame, and the magazine release can be configured for rightor left-handed operation. These features make the Sig a truly ambidextrous pistol. The P320 was designed from the ground up to be adaptable to a wide variety of missions and situations. The full-sized pistol is fine for a law enforcement duty gun or for home defense, while the compact and subcompact pistols can be tucked into a concealed holster and carried discreetly. The full-size and subcompact pistols each have their own barrels, slides, and grip frames. The carry and compact guns share barrels and slide, but each makes use of their own grip frames. The compact s shorter grip frame makes it a natural choice for concealed carry. Any P320 can accept a magazine in the appropriate caliber from the larger-sized pistols. The P320 s adaptability is taken a step further by the small, medium, and large diameter grip frames. These modules allow users with any hand size to customize the fit of the pistol to their hand. In a police department or a military unit, there may be many different users with the same type of pistol. Having the ability to configure grip modules to suit an officer s hand while maintaining interchangeability of magazines and other parts makes a lot of sense for these applications.
OPERATION The P320 is the first striker pistol in the Sig lineup. Striker designs typically utilize a single-action trigger, with the internal striker held to the rear under spring tension until released by the trigger squeeze. The Sig s trigger is partially cocked by racking the slide, but relies on the trigger pull to complete the cocking action. The P320 also has the second strike capability, meaning that if the hammer is dropped and the round does not fire, the trigger can be squeezed again. Other striker designs require the slide to be racked a second time to recock the striker. DISASSEMBLY Unlike other striker-fired pistols, the Sig does not require the user to pull the trigger in order to break the gun down. There have been many cases of negligent discharges resulting from users failing to check drop their magazine or check their chamber before pulling the trigger to disassemble their pistol. The P320 instead requires the magazine to be removed and the slide locked to the rear to take the pistol down. The full assembly and disassembly video can be viewed at https://www.youtube.com/ watch?v=6bzaaxk3ss8. CONFIGURATIONS The full-size pistol is 8 overall, with a 4.7 barrel. It is 5.5 tall and weighs 29.4 oz. with magazine. The 9mm has a 17-round magazine capacity, while the.357 Sig and.40 hold 14 rounds. The carry configuration has an overall length of 7.2 with a 3.9 barrel. The 7.2 height and magazine capacities are the same as the full-size. In compact configuration, the P320 has a 3.9 barrel, an overall length of 7.2, and overall height of 5.3. It weighs 26 oz. with magazine, and has a capacity of 15 rounds in 9mm or 13 in either.357 Sig or.40 S&W.The subcompact version has a 6.7 overall length, with 3.6 barrel. The overall height is 4.7 and weight is 25 oz. Magazine capacities are 12/10/10 in 9mm,.357, and.40 respectively. The Sig P320 is currently involved in the U.S. Army s Modular Handgun System competition to find a new service pistol. Other entries include two models from Glock, Smith and Wesson M&P, and Beretta s APX. The Sig is the only truly modular design in the contest. The MHS edition of the pistol includes an ambidextrous thumb safety, captive firing pin, and loaded chamber indicator. CONCLUSION The Sig P320 represents a step forward in strikerfired handguns. Having such a versatile design, in multiple calibers and sizes, is a tremendous advantage over the current competition. The inclusion of multiple optional safety features, both internal and external, provides unmatched adaptability to the needs of various agencies. With its modular design, updated disassembly procedure, and truly ambidextrous operation, this handgun can undoubtedly be adapted to any mission set. SOURCES CITED http://www.sigevolution.com/p320 http://bearingarms.com/bob-o/2016/06/01/droppretense-declare-sig-p320-armys-next-handgun/ http://www.guns.com/2014/10/14/the-sig-p320- army-modular-handgun-system-edition-3-photos/
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