Brownells 75th Anniversary - A Shooting Heritage

Rifle-Caliber Punch from a Small Package

The MCX Rattler PSB is a semi-auto pistol variant of Sig Sauer’s select-fire MCX Rattler SBR fitted with a Sig Brace. These pistol features make the PSB easier for the civilian to own without a long wait for NFA paperwork. Otherwise, the PSB offers all the strengths of the original MCX Rattler, including rifle-caliber .300 AAC Blackout punch and the ever-familiar AR-15 operating system in a slim, ULTRA-COMPACT package that’s easy to deploy quickly.

Built around Sig’s proven gas piston action, the MCX Rattler PSB doesn’t need a buffer tube, which contributes to its diminutive size. And with its 5.5" PDW barrel, the PSB is incredibly easy to squirrel away in a tight place - a backpack, briefcase, computer bag – until you need it. Other features:

  • 19.3" collapsed OAL
  • Uninterrupted full-length Picatinny top rail
  • Ambidextrous controls
  • Free-floating, hammer-forged carbon steel barrel with 1-5" rifling
  • M-LOK slots on handguard
  • Multiple sling-mounting options
  • Uses standard USGI-pattern AR-15 magazines

The full-size charging handle, safety selector, and mag release are all ambidextrous, so it’s easy to operate them in fast moving, high-pressure situations. The specially contoured and textured pistol grip gives your shooting hand excellent control. And the Sig Enhanced Trigger proves that a compact firearm doesn’t have to be a forced compromise with a poor trigger.

Finally, the Sig Sauer MCX Rattler PSB’s adjustable gas block enables you to shoot both supersonic and - for use with a sound suppressor - subsonic ammo from it.


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