The Maxim Defense PDX Pistol .300 AAC Blackout 5.5in Gray is a compact AR-style pistol built around Maxim Defense’s patent-pending SCW system, developed for the SOCOM PDW solicitation. It delivers close-quarters handling and modular capability in a small package, chambered in .300 AAC Blackout for versatile home-defense or range use. This pistol features a 5.5-inch threaded barrel, a 20-round magazine, and an integrated bolt carrier group with interchangeable buffer weights to reduce overall length while maintaining reliable cycling.
| Manufacturer | Maxim Defense |
|---|---|
| Model | PDX Pistol |
| Material | 7075-T6 aluminum receiver, steel barrel (per manufacturer specs) |
| Compatibility | Standard AR-15 lower parts, .300 AAC Blackout ammunition |
| Finish | Gray hardcoat anodized receiver, black nitride barrel |
| Weight | 4.8 lbs (unloaded, per manufacturer specs) |
| Condition | New |
Key Features
- SCW System – Why it matters: The patent-pending short-stroke gas system with interchangeable buffer weights lets you tune the recoil impulse for different loads, making it easier for newer shooters to stay on target.
- Compact 5.5-Inch Barrel – Why it matters: Keeps the overall length under 20 inches, so it fits in a backpack or vehicle console while still delivering .300 Blackout’s stopping power at close range.
- Integrated Bolt Carrier Group – Why it matters: The shortened carrier profile reduces receiver extension length without sacrificing reliability, giving you a smaller package without trading durability.
- Threaded Muzzle – Why it matters: Allows quick attachment of a suppressor or muzzle brake, cutting noise and flash for safer indoor shooting or quieter backyard plinking.
- 20-Round Magazine – Why it matters: Balanced capacity for home defense or range trips—enough rounds for multiple threats without adding bulk to the grip.
Who It’s For
This pistol is built for families and new shooters who want a compact defensive firearm that’s easy to handle in tight spaces. It’s also a solid choice for experienced shooters looking for a lightweight truck gun or a platform to teach responsible firearm use to teens and adults. The .300 AAC Blackout round is forgiving for beginners and effective for home defense.
Pros and Cons
- Pro: Extremely compact—fits in a small safe or range bag.
- Pro: SCW system reduces felt recoil, helping new shooters stay accurate.
- Pro: Threaded barrel suppresses easily for quieter shooting.
- Con: 5.5-inch barrel limits effective range to about 200 yards with supersonic ammo—not ideal for long-range target shooting.
Comparison: Maxim Defense PDX vs. Competitors
| Feature | Maxim Defense PDX | Zev Technologies OZ9C | Geissele Super Duty Pistol |
|---|---|---|---|
| Caliber | .300 AAC Blackout | 9mm | 5.56 NATO |
| Barrel Length | 5.5 in. | 4.5 in. | 10.3 in. |
| Weight (unloaded) | 4.8 lbs | 2.3 lbs | 6.2 lbs |
| Gas System | SCW short-stroke | Blowback | Direct impingement |
| MSRP | $2,245.50 | $1,899 | $1,895 |
| Best For | Compact PDW/home defense | Concealed carry/competition | Duty/range use |
Frequently Asked Questions
Is the Maxim Defense PDX legal to own without a tax stamp?
Yes, this is a pistol configuration with a brace, not a stock, so it’s legal as a standard firearm under federal law. Always check your state and local regulations before purchasing.
Can I use subsonic .300 Blackout ammo in the PDX?
Absolutely. The SCW system cycles both supersonic and subsonic loads reliably. Subsonic rounds are quieter with a suppressor, making them great for indoor training or home defense.
What kind of accuracy can I expect from a 5.5-inch barrel?
With quality ammunition, expect 2-3 MOA at 100 yards. It’s designed for close-quarters use, not precision benchrest shooting, but it’s more than accurate enough for defensive scenarios.
Does this pistol come with a brace or a stock?
It ships with Maxim Defense’s proprietary pistol brace, which is adjustable for length of pull. No stock is included.
What is the overall length of the Maxim Defense PDX?
Overall length with the brace collapsed is 16.5 inches, and extended is 19.5 inches. That’s shorter than many rifles with a 16-inch barrel.
Why Buy From Us
- ✅ Nationwide delivery to all 50 states
- ✅ Ships within 1-2 business days
- ✅ 30-day return policy on unopened items
- ✅ Secure checkout with encrypted payment
Looking for more compact AR pistols? Check out our AR Pistols category, or browse .300 Blackout Firearms for similar options. For accessories, visit AR Uppers & Parts.
Last updated: April 2026
FFL Transfer & Firearms Laws for Maxim Defense PDX Pistol .300 AAC Blackout 5.5in Gray
All firearms, including the Maxim Defense PDX Pistol .300 AAC Blackout 5.5in Gray, must be shipped to a licensed Federal Firearms License (FFL) dealer. You will be required to complete a background check and any necessary paperwork before taking possession.
How It Works
- Place your order online.
- Provide your preferred FFL dealer information.
- We ship the firearm directly to your FFL.
- You complete the background check and pickup at the FFL.
Legal Compliance
We comply with all federal and state firearm laws. It is your responsibility to ensure the Maxim Defense PDX Pistol .300 AAC Blackout 5.5in Gray is legal in your state. Some states may have restrictions on certain firearm models or features.
Helpful Resources
Need assistance? Contact our Miami store for help with FFL transfers and firearm compliance.
Frequently Asked Questions About This Product
Why buy Maxim Defense PDX Pistol .300 AAC Blackout 5.5in Gray from Miami Shooters Supply?
We’re a trusted firearms dealer offering fast shipping, competitive pricing, and 100% compliance with U.S. federal firearm laws. All orders ship from our licensed facility with full tracking and expert customer service.
Where can I buy Maxim Defense PDX Pistol .300 AAC Blackout 5.5in Gray?
You can purchase this item directly on our website and have it shipped to your local FFL dealer. You can also visit us in-store in Miami, Florida.
Is Maxim Defense PDX Pistol .300 AAC Blackout 5.5in Gray available now?
Availability is shown live on this page. If the “Add to Cart” button is visible, this item is currently in stock and ready to ship.
What category does this product belong to?
This product is listed under: AR Pistols.
What tags or features does this product have?
Key features and tags for this product include: .
Is this product legal in my state?
It is your responsibility to ensure this item is legal in your state or locality. We ship only to valid FFL dealers in compliance with U.S. laws. Always check your local regulations.




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