The Maxim Defense PDX-SD (brand part no. MXM-47769) is a .300 AAC Blackout short-barrel rifle finished in Arid, part of Maxim’s SDX suppressor-tuned firearm lineup. Maxim Defense builds the PDX-SD around a shorter, larger-diameter M-Kore suppressor tuned specifically for the platform, delivering an ultra-compact system that shoots full-powered cartridges while remaining hearing safe. The PDX-SD favors shooters who want an integrally suppressed, ultra-compact SBR.

Key Specifications

• Chambered in .300 AAC Blackout.
• Wears a 5.5-inch barrel.
• Feeds from a 20-round magazine.
• Finished in Arid.
• Built with Maxim’s M-Kore reflex suppressor system.

Frequently Asked Questions

Is this an NFA item? Yes. As a SBR, it’s a Title II firearm requiring an approved ATF Form 4 and transfer through an NFA-licensed dealer.

What caliber does it fire? .300 AAC Blackout.

How long is the barrel? 5.5 inches.

Buy the Maxim Defense PDX-SD SBR

This is a Title II item regulated under the National Firearms Act. Purchase requires an approved ATF Form 4, no federal transfer tax, and transfer through a licensed NFA (SOT/Class 3) dealer, with an extended federal approval wait before delivery. Order through Maxim Defense‘s short barrel rifles lineup and our Lubbock, Texas team will walk you through the transfer process.