Glock 20 Gen 4 10mm Pistol review, G20, left
(Photo by David Bahde)

Predator defense has become a real concern these days. Coyotes have become a common sight in some urban areas while cougar and bobcat have been spotted in backyards, parks and even neighborhood streets. The more we interact with predators, the bolder they become. Couple that with increased hunting restrictions and it will only get worse. Black bears have become common on trails and campgrounds and brown bears are a concern in states like Montana, Idaho, Wyoming and Alaska. Increasingly, people are looking for a carry handgun for both two-legged and four-legged predators. So how about a Glock 20?

Why the Glock 20 Gen 4 Is Your Best Bet

The wheelgun seems to be the most common recommendation for this purpose; many “experts” insist on 44 caliber or bigger. It’s hard to argue handgun power when it comes to very large bears, but you still have to get hits, and not everyone can with a revolver. We’re also at a point where at least one generation (working on two) has never seen, let alone used, a revolver. Most people carry semi-autos, and carrying what you’re familiar with might be your best course of action. Thankfully, Glock happens to offer what may be the perfect tool for the job. The Glock 20 chambered in 10mm is increasingly common in the proving ground of large predators—Alaska.

Glock 20 Gen 4 Details

Professional guides and backwoodsman are increasingly carrying the G20 and for good reason. Loaded properly, the 10mm can deliver incredible energy and deep penetration with its 15-round magazine capacity. Even as a full-sized pistol, it weighs less and carries more easily than most big-bore revolvers.

Glock 20 Gen 4 10mm Pistol review, G20, right
(Photo by David Bahde)

Glock’s proven reliability in the most difficult conditions, climates and situations makes this manufacturer a solid choice. It also offers unparalleled versatility with drop-in barrels in .38 Super, 9×25 Dillon, .357 SIG and a few I probably missed. You can easily carry the same pistol with the same sights using the same grip and feel on the streets or in the backcountry. Chambered in anything from soft-shooting 125-grain screamers with controlled expansion to 200-grain hard cast with penetration measured in yards, it will do anything required of a carry pistol.

In most cases, a factory Glock 20 will get the job done, but a few changes can really make things better. Factory barrels are polygonal, which isn’t really conducive to lead loads, and big predators are best dealt with using hard-cast lead. Adding a fully supported barrel with conventional rifling allows you to practice with lead and use the stoutest hard-cast loads for protection. Sights that are visible in any environment at both day and night are also a great option. If you’re careful, even a trigger change is possible; just don’t compromise reliability. Lastly, a simple grip reduction can be a huge help especially with hotter loads.

Making Some Modifications

Starting with a Glock 20 Gen 4, I sent the frame off to Lew Gosnell at Glock Grip Reduction. Lew has been doing grips for a couple decades and is a true expert. He provided useful texturing, a grip-angle change and a larger beavertail. Now, this G20 fits my hand and points more like a 1911. The texture also proved excellent in the snow, rain and mud, gloves or not. If you’re skipping this part, you may consider a G20 SF (Short Frame) since it fits smaller hands better, but you cannot go wrong with either.

Brownells was kind enough to provide the rest of my modifications, starting with the trigger. I wanted a better feel while maintaining factory internals, and SSVI had just the solution. Its Tyr trigger changes the leverage on the trigger using the factory bar. The result is less pull weight (4 pounds), take-up and overtravel with no adverse effect on the internal operation. Installation is simple with great video support.

SSVI Tyr Trigger, G20 Gen 4 pistol
(Photo by David Bahde)

Bar-Sto Precision makes some of the finest pistol barrels you’ll find. Super strong with fully supported chambers, the company uses standard rifling accommodating lead bullets. Mine took about 30 minutes of filing for a perfect lockup. Insanely accurate, they will outlast a generation or two of users.

Trijicon’s XR front sight is easy for me to see no matter the condition. The 10-8 Performance MOS rear sight is built solid and locks in place for use in unconventional manipulations and in rough conditions.

Glock’s standard Gen4 return spring will handle most loads, but if you intend to feed it a ton of hard cast, a recoil reducer from Sprinco is a great addition. You can swap out the mainspring for different weights and save the wear and tear on the gun and your wrists.

Finding a Holster

When it comes to carrying your predator-defense gun, the most critical aspect to consider is immediate accessibility. Chest rigs are very popular and can be handy outside lots of clothing or on a river or stream while fishing. Just make sure that you practice getting to them around your gear.

For the most part, I recommend carrying your predator-defense gun in the same place as your everyday-carry weapon, because that’s where you’ll reach first, and time is not your friend. You’ll have to work with outer clothing, but that’s true of concealed carry in general. Milt Sparks provided a 55BN, one of the best holsters you can buy, with a matching S-4C magazine pouch. Built to last, these fit tight against the body and secure the pistol. Milt Sparks’ Versa Max 2 accomplishes the same thing, except it’s designed for inside-the-waistband carry outside the trail or backcountry.

Versatility Win Action

Gunsite Academy was hosting a media event focusing on predator defense, the perfect venue for testing. Rangemasters Ed Head and Lew Gosnell ran the training, and Rob Leahy of Simply Rugged Holsters, who spent much of his life in Alaska hunting and guiding, provided some excellent information. His chest rig, the Chesty Puller, was designed based on his own bear encounter and is fantastic for revolvers and semi-automatics.

Glock 20 Gen 4 10mm Pistol review, G20, field
(Photo by David Bahde)

Dropping in my KKM Precision 40-caliber barrel, I spent most of the day using DoubleTap Ammunitions 180-grain Match load. At 960 feet per second, it’s soft shooting and fast. A .40 S&W barrel is a great investment for long range days—easier on the wrists, the pistol and the pocketbook. It proved accurate from CQB ranges to 50 yards with several loads including Federal’s 180-grain HST. Moving into the shoot house, DoubleTap’s 10mm frangible proved excellent. Using a 125-grain bullet, it pushed into the 1,500 feet-per-second range and functioned perfectly.

Four-legged predators were the topic on the second day of the event. I fed the Bar-Sto Precision barrel a healthy diet of 180-grain controlled expansion and 200-grain hard cast at 1,300 feet per second. DoubleTap’s hard-cast 10mm uses its own bullet that’s sturdy enough to use in factory barrels without buildup. These have been used to harvest Cape buffalo in Africa with deep, hard-hitting penetration. Accuracy was excellent and the recoil minimal, and it worked with Buffalo Bore, Federal and Sig Sauer 10mm loads. Over the course of two days, I successfully ran 40-caliber loads at 960 feet per second and 10mm loads from 125-grain frangible to 200-grain hard cast with just a simple barrel change using the factory Gen4 return spring.

Carry Smart

If you’re carrying a handgun for predator defense, be certain to practice in the conditions you’ll likely encounter. Shoot on the move, backwards and sideways. You may fall on your back in a real-life encounter, so learn to do so without shooting yourself in the process. Any fall might hurt, and it can make you miss—and that is just not a good scenario. Make sure that both you and your weapon of choice can get hits on target under real conditions. Practice dry and safely on the range but recognize that the backcountry is definitely not the range.

Carry enough pistol to get the job done and carry it all the time. Internet experts will tell you that the 9mm will “get the job done,” but few professional guides in Alaska will agree—especially with large bears. Just as importantly, remember that this weapon is a last resort, but if it’s not on you, it won’t work at all. You’re not going to have enough time to run to your gun; keeping it in a pack or bag has cost at least a few people their lives. Whether it’s self-defense on the street or predator defense in the woods, you cannot use what you don’t have.

Revolvers remain excellent tools for predator defense and hunting, but don’t count out the 10mm semi-automatic; you should strongly consider the Glock 20. It offers incredible versatility at a great price and may just be the perfect predator-defense semi-auto pistol on the market today. For even more info, visit

Glock 20 Gen 4 Specs

  • Caliber: 10mm
  • Barrel: 4.61 inches
  • Overall Length: 8.07 inches
  • Weight: 30.69 ounces (empty)
  • Grips: Polymer, modular backstrap
  • Sights: White-dot
  • Action: Semi-auto
  • Finish: Polymer frame/Tenifer slide
  • Capacity: 15+1
  • MSRP: $700

Glock 20 Gen 4 Performance

Buffalo Bore 220 HC2.001,270
DoubleTap 125 Barnes1.551,600
DoubleTap 155 Barnes1.601,580
Hornady 175 Critical Duty1.501,200
Sig Sauer 180 VC JHP1.751,300
Underwood 135 JHP1.701,600

Bullet weight measured in grains, velocity in fps by chronograph and accuracy in inches for three five-shot groups at 25 yards.

This article is from the fall 2020 issue of Survivor’s Edge Magazine. Print and digital copies also available at

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