Home / Products / Maxim Defense / Maxim Defense MDX 508 300 BLK Mil-Spec Complete Upper - 8.5"
Maxim Defense MDX 508 300 BLK Mil-Spec Complete Upper - 8.5"

Maxim Defense MDX 508 300 BLK Mil-Spec Complete Upper - 8.5"

Lowest Listed Price
$1,255.5
MSRP
$1,255.5
Savings
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1 Stores
Updated
Aug 26, 2026
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Specifications

MPN
MD-MDX-508-300-BLK-CU-8.5

Description

The MDX508 upper receiver is now available as a direct upgrade to your existing Mil-Spec lower receiver. It features an 8.5" barrel making it ideal for close-quarters situations. The included HATEBRAKE(TM) increases reliability and is tucked under the 9.5" handguard. These upper receiver groups ship complete, including a Maxim Defense Mil-Spec bolt carrier group. Radian Raptor charging handle, and Maxim Defense hand stop, ready to shoot right out of the box. Features: Increased reliability due to included HATEBRAKE(TM) Armorer level adjustable gas block M-slot compatible handguard Military-grade materials [17-4 Stainless Steel, 7075 and 6061 Aluminum] HK height rail for a more rigid upper receiver Installs on any Mil-Spec lower receiver Comes with Mil-Spec bolt carrier group Specifications: Weight: 3 lbs 10 oz Barrel Length: 8.5" Calibers: 300 BLK
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