The Modular Universal Pistol 1, or MUP 1, is compatible with current P320 upgraded parts, including SIG’s line of “drop safe” firearms. You can use this insert to make a 9mm, 40 S&W, 357 SIG, and 45acp (with slight modifications). That means this SIG P320 insert is extremely versatile. Design a SIG P250, a P320, or even put it in the EXO-1 Chassis system.
This quality insert is made from type 316 stainless steel, so it will last you through years of use.
Easy to Build Firearms
Since 2013, we’ve been the ultimate DIY firearm solution. With this insert, you have a base from which to build your new favorite firearm in the privacy of your own garage. To finish the insert, you need the following:
Bend Slide Rails
Trim Rails to Size
You can easily complete all of the operations on your SIG P320 insert with a Dremel, Drill Press and our MUP-1 Jig (sold separately). Follow instructions to complete a gun that looks, feels, and operates just like one from the manufacturer but without the hassle of paperwork.