Glock 21 Vs. Glock 37

The Glock automatic handgun is world famous for its stopping power, mechanical quality and reliability. Law-enforcement agencies worldwide equip their agents with the various models of the Glock handgun. Civilians often favor the Glock for personal protection as well as for target shooting. Glock manufactures more than 20 models, firing seven different calibers ranging from 9mm to .45. Two of its models, the Glock 21 and the Glock 37, are very similar in appearance and both fire .45 loads, but gun enthusiasts are generally able to spot the differences in short order.

  1. Caliber

    • The Glock 21 fires a standard .45 automatic cartridge. The 37 model fires a .45 G.A.P. load, which is a shorter load designed for a more compact weapon.

    Length/Height/Width

    • In general, the Glock 21 is slightly larger than the 37. At 7.59 inches, the Glock 21 is longer than the 37 (which is 7.32 inches long). The 37 is 5.51 inches in height, .04 inches higher than the 21. At 1.27 inches, the Glock 21 is .09 inches wider than the 37.

    Weight

    • The Glock 21 is also the heavier model. The Glock 21 is 26.28 ounces when empty, as opposed to 25.95 ounces for the Glock 37. When loaded, the 21 model is about 38.3 ounces; the Glock 37 is approximately 35.48 ounces when fully loaded.

    Magazine Capacity

    • The Glock 37 has a magazine capacity of 10 rounds. The Glock 21 can accommodate a 10- or 13-round magazine. The mass of an empty Glock 37 magazine is 2.68 ounces; fully loaded, it weighs about 9.53 ounces. The Glock 21's magazine weighs 3.1 ounces empty; fully loaded, it weighs about 12 ounces.

    Trigger Pull

    • The trigger pull, or trigger resistance, of the Glock 21 and Glock 37 are the same, as is the trigger travel (the distance the trigger moves after the shot is fired). The trigger pull of both guns is 5.5 lbs.; the trigger travel is 0.5 inches.

    Barrel rifling/Length of Twist/Safety Mechanism

    • The barrel rifling of both guns is the same: right hand, octagonal. This means that the grooves inside the barrel are in an octagonal pattern, with a right hand twist. The rifling causes the bullet to spin as it travels, making it more aerodynamic.

      The length of twist for both the Glock 21 and the Glock 37 is 15.75 inches, which means a bullet must travel 15.75 inches in order to complete a single revolution.

      Both guns feature the Internal Locking System, which, when engaged, makes the gun impossible to fire. They also have the "safe action" feature, a three-safety system designed to prevent accidental discharge. According to the Glock website, the pistol's safety features prevent the gun from firing when dropped.

    To Each His Own

    • Each weapon has its advantages depending on the preference of the gun owner. The Glock 21 is known for its light recoil and accuracy, but is a heavier weapon than the 37. The 37 model is preferred by gun owners who want a more compact weapon without sacrificing the stopping power of a .45.