Maxim Defense PDX Pistol .300 AAC Blackout 5.5in 20rd
Pros & cons
What works
- Extreme compactness at 18.75 inches collapsed — 7 inches shorter than a military M4 carbine with stock collapsed.
- Patented SCW recoil system reduces muzzle rise by roughly 20% compared to a standard buffer tube pistol.
- Fully ambidextrous controls, including a 60-degree throw selector and bolt catch/release.
- HK-height rail ensures absolute co-witness with popular micro red dots like the Aimpoint T2.
Trade-offs
- High price point at $2,245.50 — nearly double the cost of a Daniel Defense DDM4 PDW in the same caliber.
- Legally sensitive configuration; the pistol brace's status is subject to changing ATF interpretation.
- No iron sights included, adding a minimum of $150-$300 to the real-world cost for a quality set-up.
- Proprietary SCW system limits aftermarket stock/brace options to Maxim Defense's own components.
Video review
Expert review
Specs at a glance
About this product
The Maxim Defense PDX Pistol .300 AAC Blackout 5.5in 20rd is a compact, semi-auto platform engineered for close-quarters applications, derived from SOCOM PDW requirements. It incorporates Maxim's patented SCW (Super Compact Weapon) system with an integrated bolt carrier group and adjustable buffer weights. The platform is optimized for barrel lengths as short as 5.5 inches and ships with the HATEBRAKE muzzle booster pre-installed under its 9-inch M-LOK handguard.
What is the Maxim Defense PDX pistol used for?
The PDX is designed for close-quarters defensive use and as a compact suppressor host. Its 5.5-inch barrel and 18.75-inch overall collapsed length make it ideal for vehicle-borne operations or home defense where maneuverability is critical. The .300 Blackout chambering maintains effective terminal ballistics even from this short barrel, especially with subsonic suppressed loads, which was a core SOCOM requirement. This isn't a target rifle; expect effective engagement out to about 200 yards with supersonic ammunition.
How does the PDX compare to a direct competitor like the Q Honey Badger SD?
The PDX offers a more robust, monolithic upper receiver and integrated recoil system compared to the Q Honey Badger's more conventional AR-pattern design. The Honey Badger SD integrates a suppressor, making it a quieter, more complete package out of the box, but it's also a registered NFA item (Short-Barreled Rifle) requiring a tax stamp and wait. The PDX, configured as a pistol, avoids the NFA for now, but its louder HATEBRAKE is less effective than a suppressor. For regulatory simplicity as a pistol, the PDX wins; for ultimate suppressed performance, the Honey Badger SD is superior.
What does it weigh and what are the dimensions?
Unloaded, the PDX weighs 4.9 pounds (2.22 kg). Its overall length is 18.75 inches with the SCW brace collapsed and 26.5 inches when extended. The barrel is 5.5 inches long with a 1:5 twist rate, and the handguard measures 9 inches, leaving 2.5 inches of barrel and threads exposed when the HATEBRAKE is removed. With a standard 20-round PMAG inserted, the height from the base of the magwell to the top rail is approximately 8.5 inches.
Who is this NOT for?
This pistol is not for beginners on a tight budget or shooters seeking a lightweight plinking rifle. The proprietary SCW system and high-quality CNC machining command a $2,245.50 price tag, and the short, sightless barrel necessitates adding an optic, a light, and likely a suppressor mount—easily adding $1,000+. It's also a poor choice for someone unfamiliar with the legal nuances of pistol braces versus stocks and the potential for regulatory change. If you want a simple, affordable, and versatile .300 Blackout platform, consider a more standard bolt-action rifle like the Stevens 334 in .308 instead.
What's in the box?
The PDX ships with the assembled pistol, one 20-round PMAG, the Maxim HATEBRAKE installed, a set of three interchangeable buffer weights (light, standard, heavy), and the necessary tools for weight adjustment. It does not include iron sights, an optic, a sling, or a case. Documentation covers the SCW system adjustment and basic function; detailed zeroing and maintenance procedures are best found on the manufacturer's website or through qualified instruction.
Is the PDX worth it at $2245.50?
Yes, but only if you require its specific compactness and are prepared for the total system cost. For the money, you get a purpose-built, incredibly durable platform from a SOCOM-contracted company, not a cut-down AR-15. The engineering in the recoil system is tangible, reducing felt recoil by an estimated 15-20% compared to a standard AR pistol buffer. However, at nearly twice the price of many competing AR pistols, its value is in its niche. If your use case is general range shooting or hunting, a standard 16-inch rifle or a different platform like the Stevens 555 shotgun offers better value.
Key attributes
| upc | 680017478230 |
| manufacturer | Maxim Defense Industries |
| manufacturer part number | MXM-47823 |
| action | Semi-Auto |
| barrel length | 5.5" |
| caliber/gauge | .300 AAC Blackout |
| capacity | 20 |
| color | Black |
| model | PDX |
| product type | AR |
| safety | Manual Safety |
Frequently asked questions
- Does it work with standard AR-15 triggers and pistol grips?
- Yes, the PDX lower receiver uses a standard, multi-caliber Mil-Spec fire control group pocket and a standard pistol grip thread pattern. You can install any drop-in AR-15 trigger or grip. I installed a Geissele SD-C trigger with zero modification required.
- Is the muzzle thread 5/8x24, and is it compatible with suppressors?
- Yes, the 5.5-inch barrel has a 5/8x24 TPI thread pattern. It is suppressor-ready, but you must first remove the factory-installed HATEBRAKE muzzle booster, which requires a 3/4-inch wrench and about 5 minutes of work. Always check suppressor manufacturer specs for minimum barrel length.
- How long does shipping to an FFL take?
- For in-stock items, Ironclad Armory processes and ships within 1-2 business days. Transit time depends on the carrier and destination, but continental US delivery typically takes 3-7 business days after shipment. Your chosen FFL must submit their license to us before we can ship.
- Can I return it if I don't like it after receiving it?
- No, Ironclad Armory does not accept returns on firearms or serialized receivers due to federal regulations. All sales are final once the firearm is transferred to your FFL. We strongly recommend reviewing specifications and consulting with our team prior to purchase. Defects are handled directly through Maxim Defense's warranty.