Sig Sauer MCX Rattler (300 Blackout) w/Pistol Stabilizing Brace and Magpul MBUS Flip Up Sights

1 in stock


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 PSB features a 3-position telescoping pistol brace 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 PSB is the ideal choice for fast-moving operators.

Magpul MBUS Flip Up Sights

The MBUS (Magpul® Back-Up Sight) is a color injection molded, folding back-up sight. The dual aperture MBUS Rear Sight is adjustable for windage.


  • Impact resistant polymer construction provides light weight and resists operational abuse
  • Spring-loaded flip up sight easily activated from either side or by pressing the top
  • Detent and spring pressure keeps sight erect but allows for unobstructed folding under impact, etc.
  • Clamps to MIL-STD-1913 Picatinny/STANAG 4694 receiver rail and provides the same height-over-bore as standard A2 irons
  • Protective wings shield the dual, same plane flip apertures
  • Sight can still be folded with either large or small aperture in position
  • Detent knob easily and positively adjusts windage


Additional Information
Manufacturer Sig Sauer
Model MCX Rattler w/ Pistol Stabilizing Brace
Type Pistol:  Semi-Auto
Caliber 300 BLACKOUT
Action Gas Operated Semi-Auto
Capacity 30+1
Sights Magpul MBUS Flip-up Sights
Barrel Length 5.5″
Overall Length 19.3″
Weight 5.1 lbs
Pistol Brace Sig Sauer Collapsible Stabilizing Brace
Magazine One 30-Round Aluminum Magazine, Magpul MBUS Flip Up Sights
UPC Product Code 798681581306
Manufacturer SKU PMCX-300B-5B-TAP-PSB

Additional Information Content

Modern Warriors

We started Modern Warriors for the sole purpose of providing a less expensive way to enjoy our love of buying and shooting some really cool stuff. What started as a hobby has turned into a business where we have developed the experience and ability to help you enjoy our same hobby and save you money in the process.

We specialize in tactical weapons, including suppressors, short barrel rifles and full auto weapons. We have routine experience in shooting the weapons we carry, so if you want our opinion on how a weapon operates, we will gladly provide it. We also have expertise working with licensed professionals in setting up gun trusts, which is an ideal way of purchasing, owning and operating any weapon restricted by the National Firearm Act. Don’t let the word “trust” scare you. It is very easy to set one up if you have the right help.

Learn More