Glock 21 Magazines

About the Glock 21
Featuring a compact and concealable frame, slide, and barrel, the Glock® 21 is one of the best-selling striker-fired pistols chambered in .45 ACP in the world. Famed for its trustworthy performance in duty and competitive shooting applications, the Glock 21 offers the same dependable field performance that Glock is internationally known for, packed in a powerful, duty-ready package.

Built around an advanced polymer frame with Glock's iconic Safe Trigger system and engineered to be a versatile and affordable competition-ready target pistol, the G21 offers superior comfort and control in high-stress shooting scenarios. The Glock 21 also comes equipped with ambidextrous controls for improved reliability and safe handling with both right- and left-handed shooters, while the high-strength polymer frame features improved ergonomics with molded finger grooves and interchangeable grip panels and backstraps for a comfortable, non-slip grip with all hand sizes. Lastly, the Glock 21 also boasts an incredibly strong, Tenifer-treated 416 steel slide with a corrosion- and scratch-resistant Nitride finish for enhanced service life, improved muzzle velocity, and enhanced accuracy in competitive shooting environments.

What is a striker-fired fire system?
Striker-fired pistols have quickly become the most trusted and best-selling defensive and tactical pistols on the market. With a striker-fired handgun, there is no hammer present. Instead of pulling an external hammer with your thumb, or utilizing an internal hammer operated by a sear and trigger pull, striker-fired pistols require the slide to be pulled rearward, or “racked” back and released forward, pulling the firing pin rearward and capturing it under spring tension. The trigger releases the striker mechanism, allowing the spring tension to release and force the pin forward to strike the primer, firing the round in the chamber. 

Striker-fired pistols are simple in their operation because after the shooter manually racks the slide to chamber a round, each trigger pull fires a single round, ejects the spent casing, loads another round into the chamber, rearms the firing pin, and is ready to be shot again. Because there is no hammer to cock or release, the trigger pull of most striker-fired pistols is incredibly easy to pull and has low pull weights, allowing shooters of all shapes and sizes to operate the firearm more reliably under extreme stress.  

Can I Use Aftermarket Magazines with my G21 Pistol?
Like all double-stack Glock pistol models, the G21 is incredibly versatile and features the same magwell and slide design, allowing you to use most full-size Glock-pattern double-stack magazines. Plus, thanks to its popularity among professional and civilian shooters, there is an ever-growing offering of aftermarket Glock mags and tactical accessories, allowing you to use most aftermarket Glock magazines from KCI®, ProMag®, Magpul®, ETS®, and other renowned manufacturers without issue.