MUP-1 80% P320 Frame (Sig Sauer® Chassis)


Sig Sauer® 80% Universal Insert (JSD MUP-1) is Compatible with the Sig Sauer® P320 multi caliber/frame modular weapons system.  Allowing you to build subcompact, compact, carry, and full framed firearms all using the same modular chassis across multiple calibers.


**Ships in 4-6 weeks currently

Available on backorder

SKU: SIG-P320-CHASSIS-FRAME Categories: , , , , , , ,

Note: your jurisdiction may require you to be a licensed FFL or licensed gunsmith to purchase this product.

add to cart

Ships to your doorstep

100% legal in free states

Secure payment processing

Guaranteed Safe Checkout

product description


  • Made from 316 stainless steel

  • 9mm, 40 S&W, 357 SIG, and 45acp (with slight modifications).

Steps Remaining

To finish this insert and make it ready for use, the following steps must be completed:

  • Drill all holes

  • Bend side rails

  • Trim rails to size