Ready to build your own Sig P320 at home? Start here.
The Sig Sauer P320's modular design is all thanks to the internal chassis that holds all the fire control parts: The trigger, striker, safety mechanisms, pins and springs. Thanks to the 80% market, you can now invest in a MUP-1 chassis (an unfinished P320 chassis) and pair it with a factory-spec P320 lower parts kit. Both units are found right here.
First, you'll need to fabricate the MUP-1 chassis, like you would any other 80% lower receiver for a handgun or rifle. This requires cutting and drilling with hand tools. Once fabricated, you must assemble the chassis using the multi-caliber parts kit. Together, the assembled chassis is now ready to accept any of the P320's modular components: A grip module, barrel, slide, and magazine which can all be found here.
The P320 "lower", or chassis parts kit includes the internal components necessary to install all those external pieces we just mentioned above. Those internal components include:
Your build awaits.
DISCLAIMER: If you are new to the world of DIY gun building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. At 80-lower.com, we are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.
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We are a national retailer of individual components and not all products depicted on this website are legal in every state. Shipping of various products found on this website are prohibited to some states (such as California, Connecticut, District of Columbia, Hawaii, New Jersey, New York, Rhode Island, and Washington). The information, pictures, text or products presented on this website are not a representation by us, and should not be understood by you, that any product or completed firearm is legal to assemble or own in your state of residence. We encourage each and every builder to perform their own research about the state and federal laws that apply to them. It is your responsibility to understand the law and we encourage you to consult with an attorney or your local ATF representative.