Angstadt Arms MDP-9 Roller-Delayed Upper, 9mm Luger, 5.85-Inch, Black

The Angstadt Arms MDP-9 Upper (brand part number AAUMDP0906) is a 5.85-inch 9mm Luger upper built around a revolutionary roller-delayed blowback action designed to be light, small, and fully functional while reducing felt recoil compared to a straight blowback 9mm AR. The compact size and reduced recoil make the MDP-9 a strong option for a personal-defense pistol build where size and strength need to balance out. This is an upper receiver assembly only, with no lower receiver included, so it is not itself a regulated firearm.

Key Specifications

• Chambered in 9mm Luger, a widely available, low-recoil defensive pistol caliber.
• Barrel length measures 5.85 inches, sized for a compact AR pistol build.
• Rate of twist is 1:10, matched to standard 9mm bullet weights.
• Operating system is a roller-delayed blowback action, reducing felt recoil versus a straight blowback design.
• Barrel finish is black Type III hard-coat anodized, a durable, low-maintenance coating.
• Model line is the MDP-9, Angstadt Arms’ compact roller-delayed 9mm platform.

Frequently Asked Questions

Is this bare upper itself an NFA-regulated item? No. It is an upper receiver assembly with no lower receiver included, so it is not a regulated firearm on its own. Installing it on a shouldered, rifle-configured lower without a registered short-barreled rifle would require ATF Form 1 approval first.

What is roller-delayed blowback and why does it matter? It is an operating system that uses rollers to delay the bolt’s rearward movement, reducing the felt recoil and bolt velocity compared to a straight blowback 9mm AR upper of similar size.

Is this a complete rifle or pistol? No, this is an upper receiver assembly only with no lower receiver included. It ships without an FFL transfer and needs a compatible lower to complete a build.

Buy the Angstadt Arms MDP-9 Roller-Delayed Upper

This upper will ship as soon as it’s available from a Lubbock, Texas gun shop for your next compact 9mm AR build. Browse more complete uppers in our AR15 uppers selection.