ProMag Magazine Glock 21, 30 45 ACP 40-Round Drum Polymer Black

When you need serious magazine capacity for your Glock 21 or 30, the ProMag 40-round drum magazine in .45 ACP delivers the rounds without the bulk of multiple standard mags. This polymer-constructed drum sits flush on your .45 and lets you extend your range time or training sessions between reloads. Built right here in the USA, ProMag backs every magazine with a lifetime guarantee against manufacturer defects—that's the kind of confidence you want in a high-capacity reload solution.

The heart of any reliable magazine is its spring, and ProMag doesn't cut corners there. Each drum uses a precision-wound spring made from heat-treated chrome silicon wire, the same material choice you'll find in premium ammunition and precision tooling. Every magazine goes through multiple assembly checkpoints before it leaves the factory, so you're not gambling on QC.

This isn't a mag for your duty pistol or carry gun—it's built for the shooter who wants more trigger time between magazine changes at the range, in a competition setting, or during training drills. The rugged polymer body handles the weight of 40 rounds of .45 ACP without flex, and the straightforward design means no fussy loading tricks—rounds feed as they should.

Key Features

• 40-round capacity in .45 ACP—significant increase over factory Glock magazines
• Heat-treated chrome silicon wire spring for reliable feeding and spring longevity
• Manufactured and assembled in the USA
• Durable polymer construction designed for rugged use
• Lifetime warranty against manufacturer defects
• Checked and double-checked through assembly for consistent quality

Specifications

Frequently Asked Questions

Will this 40-round drum magazine work with my Glock 21 and 30?

Yes. ProMag designed this drum specifically for Glock 21 and 30 platforms, both chambered in .45 ACP. Fit and function are matched to those frames.

What's the difference between this ProMag drum and factory Glock magazines?

The primary difference is capacity. Factory Glock 21 magazines typically hold 13 rounds; this ProMag holds 40. The drum's larger footprint accommodates the spiral feed design necessary for that capacity. The spring uses heat-treated chrome silicon wire and is precision-wound to handle repeated loading cycles.

Is this magazine made in the USA?

Yes. ProMag manufactures and assembles this magazine in the United States. Each unit passes multiple quality checks during assembly.

What warranty does ProMag offer?

ProMag backs this magazine with a lifetime warranty against manufacturer defects in materials and workmanship.