Modular Chassis Insert for SIG SAUER® P320™ | Polymer80

About this product

Build Your Custom SIG SAUER® P320™ with the MUP-1 Fire Control Group Insert

Introducing the MUP-1, the premier 80% frame insert for the SIG SAUER® P320™ pistol, designed for enthusiasts and builders seeking a customizable firearm experience. Precision-machined from high-quality 316 stainless steel, this insert mirrors OEM specifications, ensuring exceptional tolerances and reliability. Compatible with a wide range of calibers including 9mm, .40 S&W, .357 SIG, and .45 ACP, it allows you to configure your P320 from scratch with various frame sizes and barrel lengths.

Key Features and Technical Specifications

• Material: 316 Stainless Steel for durability and corrosion resistance
• Caliber Compatibility: 9mm, .40 S&W, .357 SIG, .45 ACP
• Frame Compatibility: Works with P250, P320, and EXO-1 chassis systems
• Parts Compatibility: Fully compatible with OEM and aftermarket components, including pins, springs, barrels, slides, and grip modules

What You Need to Complete Your Build

To finish your P320 build, you’ll require additional components such as a P320 grip module, a lower parts kit, and slide parts. This insert is an unfinished firearm receiver, meaning it must be fabricated by the end user to become functional. As experts in the industry, Polymer80 provides top-tier products backed by years of experience, ensuring you get a reliable and high-performance build.

Important Notes and Restrictions

Warning: This is not a functional firearm in its current state. Shipping restrictions apply; it is not available in certain states or cities. Always check local laws and our policies before ordering. Orders from restricted areas will be cancelled, possibly with a restocking fee.