The 21 was Glocks biggest gun until the arrival of the models 34 and 35, which feature a longer slide and 5.3-inch barrel. The .45 ACP 21 incorporates a 4.6-inch barrel, but at about 27 ounces unloaded, it is still the heaviest pistol in the Glock lineup. This is the result of beefing up the original design to handle the pounding of .45 ACP ammunition. For example, the current 9mm Model 17, which is similar in dimensions to the GL21 and closest in design to the original Glock pistol, weighs only about 22 ounces. Our GL21 arrived with two 13-round magazines.
Palm swells and finger grooves with helpful checkering molded into place have helped the Glock pistols become more shooter friendly, and adding a rail to the dustcover allows accessories to be added easily. The magazine release is prominent, making reloading faster. The extractor offers plenty of surface area to the case rim and serves as a loaded-chamber indicator, sticking out just enough to tell the shooter visually or by touch when the gun is charged.
Removing the top end still requires a firm claw-like grip. The routine is to move the carbon steel slide to the rear about a half-inch and pull down on the locks located just above the trigger guard on each side of the frame simultaneously. This allows the slide to move forward. We think the locks could be more pronounced and easier to grab without subtracting from the snag free profile or increasing the likelihood of being activated unintentionally.
Once the top end was removed, the difference in weight between the feather-light receiver and the slide became apparent. The polymer guide rod and flat coil spring stayed together as one unit, so there were no small parts to misplace. Just a receiver, carbon-steel barrel, slide, and recoil assembly. The top end rode on four small guides that are inserted into the polymer rails of the receiver. Putting the gun back together merely required applying the top end to the frame.
The Glock design does not include a decocker, so making the gun safe after a string of fire required pressing the trigger, but only after removing the magazine and confirming that the chamber was empty. If you are used to a 1911, which can be shut off by activating the thumb safety, you may feel uneasy putting this gun down on the bench in a loaded condition. If you are in the habit of picking up a gun from the bench with the finger inside the trigger guard or think that the trigger face is part of the grip surface this gun (or any other) is not for you.
Our GL21 and GL21C pistols each arrived with a heavy trigger that provided about 10 pounds of resistance. We expected a 5.5-pound pull. At the range the large size of the gun made it easy to shoot from a sandbag rest. The weight of this trigger and the amount of take-up let us approach the trigger almost like a two-stage mechanism. But this technique was too dangerous to attempt anywhere else but from the shooting bench.
For collecting accuracy data, we fired Winchester 230-grain FMJ ammunition as well as 200-grain JHP/XTP rounds from Hornady and Winchesters 185-grain Silvertip hollow points. The Hornady ammunition proved the most powerful, moving at an average velocity of 1007 fps. Both the Hornady ammunition and Winchester FMJ rounds produced average groups measuring about 3 inches across. The Winchester Silvertips proved to be the best choice with groups ranging from 2.1 to 2.8 inches. We had no malfunctions.