Maelstrom Pro - Delayed Blowback MAC-11 Upper - 8" 9mm
RELEASE DATE TO BE DETERMINED
Product Description
The Maelstrom Pro brings delayed-blowback operation to the MAC-11 platform. It is designed as an upgrade for compatible MAC-pattern lower platforms, including traditional sheet-metal lowers and modern machined lower designs, while maintaining compatibility with standard full-size MAC-pattern bolts.
Built around our detent-delayed operating system, the Maelstrom Pro delivers a softer recoil impulse and substantially reduces visible bolt bounce* compared to traditional straight-blowback designs, while preserving the compact footprint and modularity that have made the MAC platform popular for decades.
Unlike traditional sheet-metal uppers, the Maelstrom Pro features a fully machined monolithic upper, a continuous Picatinny top rail, and a folding non-reciprocating charging handle. The result is a modernized upper assembly that combines improved ergonomics, modern optics compatibility, and delayed-blowback performance in a single package.
No proprietary bolt is required.
Uppers ship fully assembled. Bolt not included. Read about bolt compatibility and testing here.
Download the Maelstrom Upper Owner's Manual
Specs & Features
- Detent-delayed blowback operating system
- Upper and charging handle machined from billet 6061 aluminum
- Cerakote Gen II Graphite Black (HIR-146) finish
- 17-4PH stainless steel trunnion and charging handle carrier, heat-treated to H900 condition
- 8.250" barrel with Black Nitride finish
- 1:10 twist rate
- 1/2x28 muzzle threads
- 6063 aluminum free-float handguard
- Continuous monolithic Picatinny top rail
- Folding non-reciprocating charging handle
- Compatible with standard full-size MAC-pattern 9mm bolts
- Compatible with standard and dual-feed magazine configurations
What's Included
- (1) Maelstrom Pro Delayed Blowback MAC-11 Upper - 8" 9mm
*Bolt-bounce observations were based on high-speed video testing with bolts from multiple manufacturers. In the configurations tested, we observed no visible bolt bounce or only minimal bolt bounce, substantially less than with the standard straight-blowback MAC upper used for comparison. Results may vary depending on the bolt, recoil spring, ammunition, suppressor use, and other components.
A Note on Cerakote Finish: Due to our manufacturing process, individual components are coated and cured separately. While we maintain strict quality control standards, minor variations in color and sheen may occur between mating parts. You may also notice lighter coating coverage in tight internal geometry; any lighter coverage in these hard-to-reach areas is purely cosmetic and will not compromise the function of the part.
