The Maxim Defense SDX RFLX SBR (brand part no. MXM-49218) is a new evolution in integrally suppressed weapon systems, chambered in .300 Blackout and built on the battle-proven SDX platform. Maxim Defense Industries integrates its M-Kore reflex suppressor directly over the barrel, delivering a stunningly quiet 129 dB at the shooter’s ear with subsonic ammunition, finished in Arid.

Key Specifications

• Chambered in .300 AAC Blackout.
• Wears an 8.5-inch barrel.
• Feeds from a 30-round magazine.
• Built with an integral M-Kore reflex suppressor over the barrel.
• Reduces to 129 dB at the shooter’s ear with subsonic ammunition.
• Finished in Arid.

Frequently Asked Questions

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

Is this suppressed? Yes, it uses an integral M-Kore reflex suppressor built over the barrel.

How long is the barrel? 8.5 inches.

Buy the Maxim Defense SDX RFLX 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 Industries‘s short barrel rifles lineup and our Lubbock, Texas team will walk you through the transfer process.