Sig Sauer MCX Rattler Pistol Kit - 5.5" Barrel 300

Factory New Condition
FFL is required
Unit Price
Quantity Purchased
Item viewed 609 times.
Item 799588057
Location Spanish Fork, UT 84660
Shipping Buyer pays actual shipping costs for the following option(s): Overnight, 2nd Day, 3rd Day, Ground
No international shipments
Payment Visa / MasterCard, American Express, Discover, Money Order
Checkout Yes
Sales Tax
Seller must collect taxes from the following states:
UT 6.75%   
Inspection/ Return Policy

The seller of this item assumes all responsibility for this listing. You must contact the seller to resolve any questions or concerns before placing a bid. Payment must be made using U.S. dollars ($) unless otherwise stated in the listing. Firearms may only be shipped to a licensed dealer (FFL Holder). Some listed items may not be legal in every state. Complete your purchase within the law.

Please read the Item Characteristics for important listing details. You must contact your FFL transfer dealer and have them send a copy of their license with your name, username, the item and order numbers to the seller.

Need more information? Need to email the seller? Ask Seller a Question.


Rapid deployment, thin, agile and precise. This is the SIG MCX® Rattler. Featuring a 5.5" PDW barrel, the MCX platform has never been more compact or accessible. Ready to go wherever it's needed, the MCX Rattler PCB features a folding pivoting contour for stability and easy concealment. This gun was designed from the ground up to be as discrete as possible while retaining all the robust capabilities of the MCX. Free-floating M-LOK® handguards matched with a PDW upper and 5.5" barrel, the MCX Rattler PCB is the ideal choice for fast-moving operators. 

Being a custom gun shop we love to take on new builds and even change our current ones. If there is anything you would like to have removed or added to our kits give us a call or send us an email and we would be happy to accommodate you. 

This weapon is available with a 3 position pistol brace or the side folding pistol brace.


  • Operating System: Gas Piston
  • Caliber: 300 Blk
  • Overall Length: 23 in
  • Overall Width: 2.8 in
  • Height: 8.0 in
  • Barrel Length: 5.5 in 
  • Weight: 5.1 lbs
  • Twist Rate: 1:5

What you get in the box

  • Sig Sauer MCX Rattler Pistol
  • Streamlight 800 Lumens TLR-I HL Flashlight
  • Magpul Dual QD Mount Sling
  • Sig Sauer Romeo 3 Reflex Sight
  • 45 Degree Flip Up Sights
  • Magpul M3 Window 30rd PMAGs
  • Plano 36" Hard Gun Case


Check out our website for other products or custom build inquiries.
Seller provided no "Additional Terms of Sale"
Sig Sauer
MCX Pistol
Barrel Length
5 inch
5.56mm NATO
Mfg Part Number