The GLOCK Gen4 G21 .45 ACP Pistol

posted on January 17, 2012

It was about seven years ago that a Gen3 G21 joined my shooting set. I had been working with GLOCKs chambered in 9 mm and 40 S&W for a while and I was ready for a model chambered in .45 ACP. Fortunately, I was on site at a local law enforcement supply and firearms store when this particular pistol was put on display.

My G21 spent a year traveling around the country as a marketing sample. Regularly handled, but never shot, the pistol was pristine. Because it was technically a used gun, the G21 had a discounted price tag attached that could have read, "Take Me Now!" instead of a dollar amount.

In the years since this purchase, the G21 has become one my favorite .45s to shoot. Although the pistol is rather large for concealed carry, the G21 has filled all of the shooting jobs I've given it with aplomb. With the success of the Gen4 GLOCK pistols released so far, GLOCK decided to make 2012 the year the G21 is released with the latest features available.

Pistol Features
The dimensions of the Gen4 G21 .45 ACP make it a duty-size pistol, but the polymer frame reduces the unloaded weight to a reasonable 26.46 ounces. The slide is made of gas nitrate treated steel and the 4.61-inch barrel contains octagonal rifling. The Gen3 single recoil spring, supported by a polymer guide rod, has been replaced by a dual recoil spring assembly with steel supports in key locations. This new assembly promises to be durable while reducing felt recoil more effectively than the previous arrangement. This G21 arrived with GLOCK MH3 steel night sights installed, but polymer standard sights are also available.

The trigger is fitted with a 5.5-pound trigger connector, which is a GLOCK standard. Reduced trigger weight connectors are available if you want to lighten the pull. GLOCK pistols feature three independent passive safeties that sequentially disengage as the trigger is pressed. These include the trigger safety, firing pin safety and drop safety. These pistols do not have magazine safeties, meaning, the pistol will fire if the magazine is removed and a live round is in the chamber.

Another of the Gen4 features is an enlarged and reversible magazine release. This new release is a boon for shorter-fingered shooters. The wider, longer textured surface of the release, combined with the slightly reduced frame size, eliminates the need to shift the shooting hand grip in order to reach it. The polymer frame features a molded-in Picatinny compatible accessory rail. Because this is a full-size frame, the rail will accept a wide range of light and laser modules. The Gen3 pistols introduced finger grooves to the grip, and the finger grooves are still present on the Gen4 model. Not everyone wants the finger grooves, but it's a love 'em or leave 'em feature of the pistol.

The frame contains internal steel contact points to prevent undo wear and to ensure reliable function. The previous frame featured a light irregular texture on the sides with patterns of lines and squares on the back strap, finger groves and the finger rest incorporated into the trigger guard. The Gen4 has what is called a Rough Texture Frame. Small, raised, blunted pyramids cover all four sides of the grip, and raised serrations are molded into the trigger guard finger rest. This new texture is more aggressive, but it's still comfortable to shoot with bare hands.

One more change to the frame is the addition of interchangeable backstraps. Two straps and an installation tool are provided. The frame with no backstrap installed is the smallest grip size available with this model. The bare frame provides a .08-inch reduction in the distance to the trigger compared to the Gen3 frame. The installation of the small backstrap brings the frame back to the original size, and the installation of the larger back strap adds an extra .08 inches for shooters with larger hands.

At the Range
On the range, the G21 behaved just as a GLOCK is expected to, but notably better than its predecessor in certain respects. The slide cycles more smoothly on the Gen4. The reduction in recoil and muzzle flip provided by the new dual-spring recoil assembly are noticeable and welcome. The slightly smaller grip, the more aggressive grip texture and extended magazine release all worked together to make running the G21 a more comfortable and positive process.

In regard to reliability, the G21 digested a variety of ammunition with no malfunctions. This included bulk practice-grade ammo, imported steel case loads, defensive hollow points in a variety of bullet weights and hot +P rounds. The formal accuracy testing for the G21 was conducted using five consecutive, five-shot groups fired from a bench rest into targets set at 25 yards. The best single five-shot group of 2.75 inches was produced by ASYM 185-grain +P Barnes TAC-XP hollow points. The ASYM load also produced the best average of 3.05 inches. DoubleTap 230-grain brass jacketed hollow points averaged 3.15 inches, followed by Winchester 230-grain PDX1 bonded hollow points with an average of 3.3 inches.

Taking advantage of the G21's accessory rail, the range time was also used to test drive the new Gen 2 Viridian X5L green laser and light module. The 154 lumen taclight is bright and powerful. The green laser dot was clearly visible on targets at every test distance, including the 25-yard mark. The variety of programmable light and laser modes are easy to cycle through by pressing both activation switches at the same time. Lightweight and compact for all the power and features it has to offer, the X5L is an ideal accessory for the G21 or any full-size defensive pistol.

Final Thoughts
GLOCK's motto, like its pistols, is simple: Perfection. Although this statement is argued by those who disagree, GLOCK has a good deal to be proud of in its products. In fact, if the old saying is true that imitation is the sincerest form of flattery, then GLOCK should be positively blushing. Pistol manufacturers around the world have been and are still busily striving to imitate and implement the design principles that have made the GLOCK such a popular choice for over 25 years. While there is certainly nothing wrong with the Gen3 G21, the changes implemented in the Gen4 version of this full-size .45 ACP pistol can be accurately labeled improvements upon perfection.

Manufacturer: GLOCK;
Model: G21
Action: Safe Action
Caliber: .45 ACP
Finish: Gas Nitrate
Grips: Multiple Backstrap System
Sights: Standard or Night Sights
Barrel Length:
Overall Length: 8.23”
Height: 5.47”
Width: 1.28”
Weight: 26.46 ozs., Unloaded
Capacity: 13+1 Rounds
Twist: 1:15.75” RH
Rifling: Octagonal
Accessories: Hard Case, Two Magazines & Speed Loader, Two Backstraps with installation tool, Cleaning Set
Suggested Retail Price: $687 Standard Sights, $734 Night Sights


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