Maxim Defense MDX .300 AAC Blackout AR Pistol, 5.5-inch Barrel, FDE, PDW Brace, Ambi Controls, M-LOK Handguard
This Maxim Defense MDX is a compact .300 AAC Blackout AR pistol built for maneuverability and control. It features a 5.5-inch threaded barrel with a blast-forward muzzle device, an FDE finish, and a PDW-style collapsing brace. Ambidextrous controls, a free-float M-LOK handguard with QD sockets and a hand stop, and a continuous 1913 top rail round out a well-equipped, USA-made package in excellent condition.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: This firearm is in great shape. There are minor, superficial scratches and blemishes present.
What’s Included
- Maxim Defense MDX .300 AAC Blackout AR pistol (FDE, 5.5-inch barrel)
- 1x 20-round Lancer L5AWM 300 BLK magazine (polymer body with steel feed lips)
The MDX platform delivers a highly compact .300 BLK setup with a 5.5-inch threaded barrel and a blast-forward muzzle device that is largely enclosed by the handguard. The short overall configuration is built around a direct-impingement operating system and a semiautomatic action on the AR-15 platform.
The free-float aluminum M-LOK handguard includes integrated QD sling sockets and a front hand stop. A continuous 1913 top rail runs across the upper and handguard for straightforward mounting of compatible accessories.
Controls are thoughtfully configured with an ambidextrous safety selector, a Radian Raptor-LT ambidextrous charging handle, and an additional right-side bolt catch/release. The lower features a flared integral trigger guard, a beveled magwell, and a curved trigger, along with forward assist, shell deflector, and an ejection-port cover on the upper.
The PDW-style collapsing brace uses dual guide rods with a rear strap for a compact footprint and quick adjustment. The pistol wears an FDE finish across its aluminum receivers and brace, and it includes a Reptilia pistol grip for a secure, ergonomic hold.
Capacity is 20+1, and this pistol includes one 20-round Lancer L5AWM 300 BLK magazine. Made in the USA, this MDX comes in excellent overall condition, with a clean, mirror-finish bore and sharp rifling.