Glock 31 .357 SIG
This gun functioned reliably, felt great, and shot accurately enough for a defensive handgun. The Glock 31 wasn’t handsome, but it was reliable. Also, its human engineering was first rate, and accuracy was better than we expected.
In our view, defensive firearms must first be reliable. Glock pistols are known for functioning flawlessly, and our Model 31 wasn’t an exception. The pistol readily digested all of the .357 Sig ammunition we fed it. In fact, it was the only handgun in this test that was 100-percent reliable. This alone was enough to give the Glock the top spot in this test.
However, the Glock 31’s accuracy was also slightly above average. Its smallest five-shot groups averaged 2.58 inches at 25 yards with both Remington 125-grain and Federal Premium 150-grain jacketed hollow points. We also obtained decent 3.18-inch groups with UMC 125-grain metal case ammunition.
Moreover, our shooters thought the Glock 31’s biggest strength was its handling qualities. The pistol was muzzle-heavy enough to make the gun feel stable, without significantly slowing target acquisition. The shape of the frame and its integral grip allowed the pistol to sit unusually low in the shooter’s hand, positioning the hand closer than normal to the bore’s axis. This improved the shooter’s ability to control the gun, especially when firing fast follow-up shots. Muzzle flip generated during recoil was only a little heavier than what a Glock .40 S&W pistol produces. Like all Glock pistols, the Model 31’s controls were user friendly. The manual trigger-blocking safety was built into the trigger. When the shooter pulled the trigger, the safety disengaged and allowed the trigger to move rearward for firing. Right-handed shooters could readily depress the magazine-release button at the rear of the trigger guard with the thumb of their shooting hands, while left-handed shooters could just as easily depress the release with their trigger fingers. The slide-catch lever on the left side of the frame worked positively. The Glock 31’s Safe Action trigger wasn’t a true double-action-only trigger, because it didn’t have a second-strike capability. However, the pull felt like a lightweight double action–only pull. The trigger’s long movement let-off at a reasonable 6.5 pounds with no noticeable overtravel.
Minor faults we found with the Glock 31 included problems with the magazine, wherein inserting more than seven rounds into either of the two 10-round steel-reinforced polymer magazines required extreme effort, even when using the loading tool provided with the gun. Both of the sights were made of black plastic, which we don’t think will be as durable as steel.
Originally Published In March 1999.