Glock 21 Gen 4

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Glock 21 Gen 4 Gun Stats

Glock 21 Gen 4

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Remarkable for its accuracy and light recoil, the GLOCK 21 Gen4 delivers the legendary stopping power of the .45 AUTO round with 10 round magazine capacity. The Modular Back Strap design on the G21 Gen4 lets you instantly customize its grip to adapt to an individual shooter's hand size. The surface of the frame employs the new scientifically designed, real-world-tested, Gen4 rough textured technology. Internally, the new GLOCK dual recoil spring assembly substantially increases the life of the system. A reversible enlarged magazine catch, changeable in seconds, accommodates left or right-handed operators. The Gen4 system is the perfect complement to this iconic .45 caliber cartridge.

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Glock 21 Gen 4 Specs

1 Category

Technical Data


.45 Auto (.45 ACP)


Safe Action







Barrel Length


Gun Type







26 oz


1.35 Inches



Glock 21 Gen 4 Features

The Glock 21 Gen 4 is a semi-automatic .45ACP with a polymer frame and a standard 13 round magazine capacity.  It exhibits all of the features of 4th Generation Glock production including a light / laser rail, reversible magazine release, finger grooves, and an aggressive texturing around all sides of the grip.

Glock 21 Gen 4 Ballistics

.45 Auto (.45 ACP) Ballistic Data
Range (Yards) Drop (inches) Velocity Energy Wind drift (inches) Time (milliseconds)
0 0 0 0 0 0
50 0 0 0 0 0
100 0 0 0 0 0
150 0 0 0 0 0
200 0 0 0 0 0
250 0 0 0 0 0
300 0 0 0 0 0
350 0 0 0 0 0
400 0 0 0 0 0
450 0 0 0 0 0
500 0 0 0 0 0

Glock 21 Gen 4 Capacity

Chambered in the heavy-hitting .45 Auto, the Glock 21 ships with 10 or 13 round magazines, while Glock also offers an extended 26 round magazine.

Glock 21 Gen 4 Ergonomics

Utilizing a double-stack, single-feed .45 caliber magazine, the grip size may feel too large for smaller-handed users.  The grip features effective texturing and finger grooves for positive control and the serrations on the back of the slide assist in cycling the slide while reloading.

Glock 21 Gen 4 Fit & Finish

The build quality of the Glock 21 is exactly what you would expect out of any Glock.  The nDLC coating is consistently applied across the slide, and the polymer frame is free of any overpress defects from the injection molding process.
Fit and Finish

Glock 21 Gen 4 Concealability

The Glock 21 Gen 4 measures over 8 inches long and 5.5 inches tall making it difficult for concealed carry without heavy clothing or utilizing a shoulder holster.  The Glock 21 is better suited for open carry or concealed winter carry.

How much is a Glock 21 Gen 4 worth?

In 2024 a new or used Glock 21 Gen 4 value varies depending on supply and demand. In the last 12 months there is great demand for a Glock 21 Gen 4 and most handguns. The Price for a Glock 21 Gen 4 has increased in cost by $0.00 in 2024 compared to 2023.

Estimated New and Used Values for a Glock 21 Gen 4 Values are based on a basic model with no options or colors.

Condition Trade-In Private Party Dealer
New In box $359.85 $470.57 $553.61
Excellent $332.17 $442.89 $498.25
Very Good $304.49 $442.89 $498.25
Good $276.81 $415.21 $470.57
Fair $193.76 $359.85 $442.89
Poor $138.40 $276.81 N/A

Gun Value Conditions explained:

New in box - 100% condition in unopened box. Excellent - 95%+ condition with or without box.

Very Good - 90% - 95% condition (all parts/finish should be original).

Good - 80-90% condition (all parts/finish should be original).

Fair - 30% - 80% condition, parts, and finish may or may not be original. Must function properly and shoot.

Poor - under 30% condition. Firearm has severe wear and tear, does not function, or is damaged.

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