Promag Smith & Wesson 5900 9mm Handgun Magazine Black Polymer 50/rd

The ProMag Smith & Wesson 5900 9mm handgun magazine delivers 50-round capacity in a reliable, field-proven polymer and steel design. Built for high-volume training, competition, and tactical applications where standard-capacity magazines limit sustained fire, this drum magazine combines modern injection-molded polymer housing with traditional stamped and welded steel components to deliver durability that matches factory-grade specifications.

Construction centers on a proprietary DuPont Zytel-based polymer drum housing paired with a full-length internal steel insert in the magazine upper tower—stamped and welded using the same methods employed in OEM Smith & Wesson factory magazines. This hybrid approach combines polymer's weight savings and corrosion resistance with steel's proven strength under sustained compression cycles. The 50-round capacity eliminates frequent magazine changes during extended range sessions, force-on-force training, or dynamic shooting drills. The black polymer finish resists UV degradation and provides the low-visibility profile operators require in tactical environments. A lifetime manufacturer defect warranty backs every ProMag magazine against materials and workmanship failures.

This magazine suits competitive shooters, law enforcement trainers, and civilian firearms enthusiasts who conduct high-round-count range sessions with S&W 5900-series duty pistols. The extended capacity addresses the practical limitation of 15 and 17-round factory magazines when zeroing, diagnostics, or qualification courses demand sustained strings of fire. ProMag drums also serve armory stock augmentation for departments running pistol fundamentals training with multiple shooters cycling through limited firearm inventories. Made in the USA, the magazine balances aftermarket affordability with domestic manufacturing quality.