8 Common GLOCK 20 Gen 4 Problems: Troubleshooting and Fixes

GLOCK 20 Gen 4 Problems: The GLOCK 20 Gen 4 is a powerful firearm that excels in accuracy, even when shooting at long distances. It stands out due to its use of advanced polymer, which significantly reduces the kickback or recoil, even though it fires heavy ammunition.

For hunters, especially those pursuing large game, this 10mm Auto pistol proves to be a dependable companion. It ensures a safe and precise finishing shot, enhancing hunting experiences.

One remarkable feature of this pistol is its Modular back strap system. This innovative design allows users to quickly adjust the grip to fit their hand size perfectly. Additionally, the reversible magazine catch makes it versatile and suitable for both left and right-handed shooters.

Now, before you decide to acquire the GLOCK 20 Gen 4, there are important considerations to keep in mind. This article aims to provide you with valuable insights into these aspects and offers solutions to potential problems that may arise during usage.

To offer a comprehensive perspective, we will also include feedback from users who have used this pistol in various scenarios. Their real-world experiences will shed light on how the GLOCK 20 Gen4 performs in practical situations. So, continue reading to gain a thorough understanding of this firearm.

Specifications & Features of GLOCK 20 Gen4

Place of originAustria
ManufacturerGlock Ges.m.b.H.
Unit cost (MSRP)$611.99
DimensionsWidth (Overall): 34 mm
Barrel Length117 mm
Magazine CapacityStandard: 15
Length of Twist9.84 inches
WeightWith empty magazine: 870 g
Caliber10 mm
Front SightWhite-dot
SafetySafe Action
Trigger Pull28 N
Overall Length205 mm
 Height incl. Mag.: 140 mm

Common GLOCK 20 Gen 4 Problems with Solutions

Common GLOCK 20 Gen4 Problems with Solutions

The GLOCK 20 Gen4 is known for its versatility, capable of firing a wide range of ammunition, from lighter to heavier loads. This versatility makes it suitable for various applications, whether for personal defense on the streets, safeguarding your home, or even venturing into the wilderness for hunting.

However, like any firearm, it’s important to be aware of common issues that users may encounter with the GLOCK 20 Gen 4:

  1. Recoil Spring Problems: One common problem is related to the recoil spring assembly (RSA). When firing heavy loads, the frame of the gun with the stock RSA can experience wear and tear.
  2. Extractor Blow-Up: This issue occurs approximately every 15 to 30 rounds. After firing, the next round in the magazine may not properly chamber, leaving the casing halfway inside the chamber, and preventing the firearm from cycling correctly.
  3. Failure to Feed: Some users have reported that the GLOCK 20 Gen 4 struggles to feed ammunition, particularly with powerful loads. It tends to function better with less potent ammunition, but hotter loads like the Underwoods 180gr TMJ can exacerbate this problem.
  4. Trigger Problem: While the gun may perform well with “regular” loads, users have reported issues with trigger reset when using hotter loads.
  5. Ejector Issue: If the ejector fails to function correctly, casings may become stuck in the chamber, preventing the firearm from firing again.
  6. Stovepiping: Stovepiping is a common issue where spent casings fail to eject properly from the chamber during the firing process.
  7. Jamming Issue: A jamming issue occurs when the gun fails to fire properly or when the bullet does not fully eject from the chamber, causing a malfunction.
  8. Heavier Trigger Pull: Many gun owners have noted that high-caliber firearms like the GLOCK 20 can have a heavier trigger pull, which may affect accuracy and user experience.

Now that you’re aware of these common problems associated with the GLOCK 20 Gen 4 handgun, let’s take a closer look at each issue and explore potential solutions in greater detail.

Problem #1: Recoil Spring Problems

The frame of the gun with the stock Recoil Spring Assembly (RSA) takes a beating when using heavy ammunition. The Gen 4 RSA may stack up and prevent proper slide-to-frame contact, even with high loads.


Inspect the area on the frame where the slide contacts during recoil, right in front of the front slide lugs. If there’s minimal damage or just a light imprint, you’re good. However, if you notice significant damage and plastic deformation, consider upgrading the spring.

A recommended solution is to use a KKM barrel and a 22lb flat IMSI recoil spring assembly. KKM barrels are known for their quality, precise fit, and exceptional machining.

Problem #2: Extractor Blow-Up

After firing approximately every 15 to 30 rounds, the next round in the magazine remains partially inside the chamber, preventing the subsequent round from feeding. This could be caused by a damaged extractor.


  1. Perform a slide teardown to inspect and address anything affecting extractor tension. Replacing the extractor may be necessary.
  2. Ensure that the plunger pin is properly seated when reinstalling the extractor.

Problem #3: Failure to Feed

The gun struggles to feed powerful ammunition, especially hotter loads like Underwoods 180gr TMJ, due to high slide speeds. Both the heavier RSAs in Gen 3 weapons and the Gen 4 dual spring exacerbate feed difficulties. Grip pressure can also influence this issue.


  1. Consider using some Wolf springs along with updated followers in your magazines. Lighten your grip on the firearm.
  2. Replace the magazines with updated followers and consider polishing the feed ramp to improve feeding reliability.

Problem #4: Trigger Problem

The gun functions well with “regular” loads, but the trigger fails to reset when using hotter loads. The spring can shift to one side during assembly, causing it to rub against the housing and impede the trigger bar’s movement for reset.


  1. You can adjust the spring without disassembling the pistol if it has shifted off to the side.
  2. To reposition the spring, use a thin tool (such as the rear edge of a small paring knife) to push it back to the center, allowing for proper trigger reset.

Problem #5: Ejector Issue

The ejector is responsible for extracting spent casings from the chamber. When it fails, a casing can become stuck, rendering the firearm inoperable. Common causes include wear and lack of maintenance.


  1. Disassemble your firearm and carefully inspect the ejector. If it appears bent, corroded, or worn, replace it.
  2. Thoroughly clean the ejector and the surrounding area to remove any dirt or debris causing issues.
  3. Apply a small amount of lubricant to the ejector to ensure smooth operation.
  4. Reassemble your firearm and test to ensure the ejector functions correctly.

Problem #6: Stovepiping

Stovepiping occurs when spent casings fail to eject properly from the chamber, potentially causing misfires and jams. Causes include a weak recoil spring, a dirty or unlubricated weapon, and a damaged extractor or ejector.


  1. Inspect the recoil spring and replace it if necessary to ensure sufficient force for proper ejection.
  2. Thoroughly clean and lubricate your firearm to facilitate smooth ejection.
  3. Inspect and replace any damaged extractor or ejector components to guide casings out of the chamber.

Problem #7: Jamming Issue

Jamming occurs when the gun fails to fire properly or the bullet does not fully eject from the chamber due to various factors, including a dirty firearm, damaged magazine, poor maintenance, or weak ammunition.


  1. Disassemble and clean your firearm meticulously, ensuring all components are free from dirt and obstructions.
  2. Check the magazine for damage and ensure it is fully seated in the firearm.
  3. Lubricate all moving parts with appropriate gun oil.
  4. Consider trying different ammunition brands to find the best fit for your firearm, avoiding low-quality, weak rounds.

Problem #8: Heavier Trigger Pull

High-caliber firearms like the GLOCK 20 may experience a heavier trigger pull, often caused by a primer bulge on the cartridge or a dirty trigger mechanism.


  1. Ensure your firing pin is straight and properly aligned to prevent primer bulges.
  2. Check the quality of your ammunition to avoid rounds prone to bulging or deforming.
  3. Clean the trigger mechanism by disassembling your firearm and using a suitable gun cleaner and oil to remove dirt and grime, ensuring a smooth trigger action.

By addressing these issues and implementing the recommended solutions, you can enhance the reliability and performance of your GLOCK 20 Gen 4 handgun while promoting safety and accuracy.

CZ P07 Problems: Troubleshooting and Fixes

User Reviews for GLOCK 20 Gen 4

User Reviews for GLOCK 20 Gen 4

First off, users really like this gun! It’s sturdy and can hold 15 rounds in the magazine, plus one in the chamber. That’s quite a lot of firepower. People especially prefer the Gen 4 model because it has a textured grip and a larger magazine release button compared to the G20SF.

When it comes to shooting .40 caliber ammo with a modified barrel on the GLOCK 20 Gen 4, users find that it handles the recoil pretty well. This means the gun doesn’t kick back too hard, making it easier to stay on target. Some users even mention that if you’re accurate with your shots, you can use it for hunting at longer distances.

However, there’s a drawback that some users have pointed out. If you don’t reload your own ammunition, using the GLOCK 20 Gen 4 can get a bit expensive. Ammo costs can add up, especially if you like to shoot a lot.

If you’re using standard ammunition loads at or slightly above the maximum recommended, the Original Equipment Manufacturer (OEM) barrels should work fine. But here’s a tip: don’t push your ammo into the “Twilight Zone,” which means going way beyond the recommended maximum loads. Doing that can put extra stress on your cases, causing bulges and creases near the feed ramp area of the barrel.

Overall, most users really love this gun despite the potential ammo cost. It’s strong, has a good magazine capacity, and handles recoil well. If you’re into firearms, this one might just put a smile on your face too!

Frequently Asked Questions About GLOCK 20 Gen 4

What is the difference between a GLOCK 20 and a Gen 4 GLOCK SF?

The primary differences between the GLOCK 20 and the Gen 4 GLOCK 20 SF lie in grip size and customization. The Gen 4 features a thinner and more comfortable grip, along with adjustable backstraps for personalized fit.

It also has a different recoil spring assembly and a more aggressive grip texture.

What is the difference between the GLOCK 20 Gen 3 and 4?

The Gen 4 GLOCK has a rougher grip texture, adjustable back straps for a better fit, three magazines instead of two, a larger magazine release button, and a different recoil spring compared to the Gen 3.

How many mags come with the GLOCK 20 Gen 4?

The GLOCK 20 Gen 4 handgun comes with either three standard 15-round magazines or three 10-round magazines, which are designed to comply with different city or state restrictions on magazine capacity.

When did GLOCK 20 Gen 4 come out?

The GLOCK 20 Gen 4, along with the entire Gen 4 series, was introduced to the public in 2010.

How much does a new GLOCK 20 Gen 4 cost?

The MSRP of GLOCK 20 Gen 4 is $611.99.

Leave a Comment