The Sig Sauer P320 Fire Control Unit (brand part no. 8900160) is the serialized, semi-automatic core of the modular P320 platform, finished in gold and rated for 9mm Luger, .40 S&W, and .357 SIG configurations depending on the grip module and slide it’s paired with. Unlike the polymer grip module surrounding it, this fire control unit is the legally regulated firearm in Sig Sauer’s modular system — the grip module, slide, and barrel are all interchangeable accessories built around this one serialized part. It ships without a thumb safety, matching the standard striker-fired P320 configuration most shooters expect.

Key Specifications

• Rated for 9mm Luger, .40 S&W, and .357 SIG configurations.
• Operates as a semi-automatic action.
• Finished in gold.
• Ships without a thumb safety, standard striker-fired configuration.
• Shipping weight of approximately 0.7 pounds.
• Compatible with a range of P320 grip modules across the modular lineup.
• Sig Sauer’s modular P320 system was designed around this Fire Control Unit as the constant, serialized part.
• Serves as the constant, serialized core across Sig Sauer’s entire modular P320 lineup.
• Sig Sauer machines this Fire Control Unit to the same tight tolerances used across the modular P320 lineup.

Frequently Asked Questions

Is this the serialized firearm or an accessory? This Fire Control Unit is the serialized firearm — the grip module, slide, and barrel around it are accessories.

Does this have a thumb safety? No, it ships without a thumb safety in the standard configuration.

Buy the Sig Sauer P320 Fire Control Unit

Build your modular P320 around a genuine Fire Control Unit from Sig Sauer. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL, and see our full handgun parts selection.