Maxim Defense PDX Upper | .300 AAC Blackout | 5.5 in

The Maxim Defense PDX U.R.G is a compact complete upper built to install on any Mil‑Spec lower receiver. This configuration pairs a short 5.5 in barrel with Maxim’s patent‑pending HATEBRAKE Muzzle Booster and a Direct Impingement operating system. The design prioritizes reduced recoil and a reduced flash signature for short-barrel AR platforms while preserving accuracy at typical short-range engagement distances. Applications include close‑quarters work and short‑range precision/range training.

Product Specifications

• The caliber is .300 AAC Blackout.
• The barrel length measures 5.5 inches.
• The overall length is 14 inches (manufacturer specification).
• The finish is Matte.
• The color is Flat Dark Earth.
• The model is PDX by Maxim Defense Industries.
• The product type is Upper and the subcategory is Complete Upper Receivers.
• The unit uses a Direct Impingement system.
• The upper is designed to install on Mil‑Spec lower receivers.
• It includes the patent‑pending Maxim HATEBRAKE Muzzle Booster to reduce recoil and decrease flash signature, per manufacturer information.
• The manufacturer marketing name is PDX U.R.G.
• UPC: 680017478261.

Compact and purpose‑built, the PDX upper provides a short-barrel option for operators and enthusiasts who need a small, manageable AR upper for short-range applications and dedicated range work. Its combination of a 5.5 in barrel, Maxim’s muzzle booster, and Mil‑Spec compatibility make it a practical choice for users building compact AR platforms where minimal length and controllability are priorities.