The Promag S&W 5900 9mm 50-Round Drum is built for shooters who demand high-capacity reliability without sacrificing fit or function. Engineered as a true workhorse, this drum mag pairs a rugged DuPont Zytel polymer housing with a precision steel upper to deliver a factory-like interface with your Smith & Wesson 5900-series platform. The heavy-duty polymer shell resists impacts and scuffs while keeping weight down, and the steel top plate provides the rigidity required for smooth insertion, solid lockup, and consistent feeding under real-world conditions.
Capacity and feeding are where the Promag drum shines. With room for fifty 9mm rounds, it eliminates frequent reloads and keeps sustained shooting sessions flowing. Feeding is driven by a heat-treated stainless steel wire spring that resists sag and binding, and an injection-molded polymer follower that tracks cleanly through the drum’s feed path. That combination reduces the common failure points of high-capacity designs so you get dependable performance shot after shot.
Durability and practical design were clearly priorities. The Zytel construction stands up to range abuse, environmental exposure, and routine handling while remaining light enough to carry. The polymer follower and internal components are engineered to minimize friction and wear, and the steel upper is machined to tight tolerances so alignment and lockup feel precise—no loose wiggle or sloppy fit that can cost you function when it matters. Maintenance is straightforward: the drum disassembles for cleaning and inspection, and the corrosion-resistant spring and steel components are built to last.
Whether you’re training, preparing for extended range sessions, or outfitting a defensive rig that benefits from extra rounds, this drum delivers a reliable high-capacity option that plays well with existing S&W platforms. Made in the USA, it reflects Promag’s focus on practical, resilient accessories that shooters can trust. While large-capacity magazines aren’t for every setup, having one engineered with quality materials and attention to feeding mechanics gives you an option when long strings of fire are part of the mission.
Rugged, functional, and purpose-built, the Promag S&W 5900 9mm 50-Round Drum blends durable DuPont Zytel polymer construction with a steel upper and stainless spring for dependable high-capacity performance.
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