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Personal Defense Handguns Semi Auto

Glock 20 Gen 4 Review

by Payton Miller   |  August 14th, 2013 11


Since its introduction in 1983 in the star-crossed, CZ-75-inspired Bren Ten, the 10mm Auto cartridge has followed an all-too-familar trajectory curve in terms of popularity. It has gone from “The Next Big Thing” to cult status, having been pushed along the way by the almost-unprecedented acceptance of the .40 S&W.

However, the 10mm Auto is still considerably more potent than the .40 S&W. And chambered in the Glock 20, it represents about the upper limits of ballistic potential you’re going to get in any real-world auto pistol.

I’d owned an S&W Model 610 10mm revolver a long time ago, and, as much as I liked it, I really couldn’t justify keeping a 61/2-inch N-frame with anything less than “44” stamped on the barrel. Prior to that, I’d heard sea stories about the 10mm’s power from old fans of the Colt Delta Elite, however, and had always wanted to try it in a self-loader. The Gen 4 Glock 20 seemed like a natural—15+1 rounds on tap from a 271/2-ounce platform that resembled a Glock 17 (a pistol I admire) on steroids. I’d seen a lot of hog hunters packing earlier-generation versions of the 20 and figured that if there was such a thing as a serious hunting auto, this would be it.

Since the Glock 17 9mm is pretty much the dimensional yardstick of the company line, the 20 has a 7.59 OAL compared with the 17’s 7.32 OAL and an unloaded weight of 27.6 ounces compared with the 22-ounce weight of the 17. The grips are wider and beefier to accommodate the larger cartridge, of course, but the difference really isn’t all that radical. Yes, it’s a bigger gun than the 17, but the magazine capacity (15+1) is almost as impressive. And the power level of full-house 10mm loads (we’re not talking late-1980s “10 Lite” here) are a lot closer to the .41 Magnum than they are to the 9mm Parabellum.

Basically, the Gen 4 Glocks feature a more aggressive nonslip frame surface; replaceable backstraps and enlarged magazine-release catch; a notched magazine to allow a more positive operation; and a dual recoil-spring assembly to increase spring life and decrease felt recoil. To be honest, when I shot a Gen 4 17 9mm, I was unable to perceive any real difference as opposed to earlier models. However, the 10mm Glock 20 was soft-shooting enough to convince me that the dual-spring setup was doing something good. The Gen 4 20 did a commendable job of taming the 10mm. In fact, it was considerably less obnoxious than .357 SIGs I’ve shot in terms of muzzle upflip and general squirminess. However, the 10mm is a concussive number, and I would not care to shoot one without all the ear protection I could get.

My pre-range ammo roundup was complicated a bit by the fact that the world isn’t exactly awash with 10mm ammo. However, what is available is pretty impressive. I was able to lay hands on two energetic numbers from Buffalo Bore featuring a 180-grain Barnes JHC and a rather intimidating 220-grain Hard Cast. Both are called “Heavy 10mm,” and that’s as good an example of truth in advertising as you’re likely to find. The 180-grain load is factory rated at 1,350 fps, while the 220-grain is said to come in at 1,200 fps. The averages I got were 1,264 and 1,145 fps, respectively, from the Glock’s 4.6-inch barrel. I have little doubt that slightly more barrel would result in meeting, or surpassing, factory claims.

The next load I used was Hornady’s Critical Defense offering that features a 165-grain FTX at a claimed 1,225 fps. My average was 1,162 fps, but the load delivered a very uniform extreme spread of 25 fps. My final load was the legendary Norma 170-grain JHP, a number that pretty much made the 10mm’s reputation back in the day. This one was every bit as hot as I remember from my time with the S&W Model 610, averaging nearly 1,249 fps.

In terms of 25-yard accuracy, the top performers were Buffalo Bore’s 220-grain HC and Hornady’s Critical Defense FTX. It took awhile for me to once again get the hang of the Glock trigger (which broke at a reasonably short, crisp five pounds). Once I’d settled down, pretty much everything stayed under three inches. In all fairness, I was plagued with flyers. I’d get four shots into a nice cluster (sometimes as tight as less than an inch-and-a-half) and then tank things with an errant shot. I liked the white-outline rear/white-dot front sights on the gun and the squared-off triggerguard. I know it’s not considered proper form in certain circles to wrap a finger around the front of the triggerguard, but I often do.

Function-wise, the Gen 4 20 ran like you’d expect a Glock to run. Which is to say, no problems. No stovepipes. No failures to feed. No failures to go into battery. The minimal amount of controls, the revolverlike simplicity of operation, the relatively soft-shooting characteristics of the gun made me realize why guys who are so fond of this model are the way they are. And one other nice thing about it is the fact that it comes with three — count ’em, three — magazines, plus a mag-loading tool (which I didn’t use because I didn’t have any problems stoking the magazines without it).

Although a lot of fans of the Glock 20 — of any generation — undoubtedly see it as a defensive tool, to me it seems best-suited to be a general-purpose outdoorsman’s gun. As a primary or secondary hunting tool for deer and hogs at reasonable yardages, I don’t think there’s another auto in the class of the Gen 4 Glock 20. As a last-ditch outdoor emergency tool? Again, tough to beat.


G&A Art Director Mike Ulrich tries his hand with the Gen 4 Glock 20.

Find out about the price and availability of the firearm covered in this article at, where you will gain instant access to the inventory of Davidson’s Inc., one of the nation’s largest factory-authorized firearm wholesalers. customers know instantly if the firearm is available and can select from offers presented by dealers in their area. The selected dealer then immediately ships the firearm via Federal Express. Perhaps best of all, guns purchased at are covered by Davidson’s Guaranteed Lifetime Replacement Program. Fast. Easy. Hassle-free.

  • Randy

    Just a quick question. You say you used a rather intimidating 220-grain Hard Cast bullet. I thought that with Glock’s polygonal rifling, firing lead bullets was a taboo. As a matter of fact, I have seen 2 mod 27’s blow up. Is there a difference with the Gen 4 models?

    • Ricerrick

      Read buffalo bores web site under there 10mm hard cast load for sale, that will explain what your asking. Simple wander is glock says no lead for liability reasons. Hardcast is much much harder then regular lead, and does not produce much leading.

  • greenwrench

    Loaned my Glock 20 Gen 3 to a friend who took it hog hunting. He shot a 200 pound pig at 40 yards using 170gr. hard cast an the bullet went through the pig.Said he was dead before he hit the ground.I also have a 20C gen3,these guns are amazing.
    To answer the question about Hard cast, yes you can shoot Hard Cast in the Glock,but at your own risk.I shoot Hard Cast from Missiouri Bullet Co. with a Brinell hardest of 18 and have no problem.I also shoot them in my 357sig,40s&w,45acp,and 10MM which by the way are all Glocks with factoy barrels.I do check my barrels after shooting the H/C,as of this date no problems.Having shot about 500 in each gun.

  • JWD

    i have a 20 gen 3 and it’s one of my favorite handguns and my go to for winter CC when i have a lot of field jacket to cover it up.

  • Jermaine Jackson

    Is this gun only used for hunting or can it be home defense as well?

    • Mazryonh

      If you can master the recoil and know when to shoot without putting a bullet through a bunch of your home’s walls, then of course it’s suitable for home defense.

    • J

      10MM is a great defensive round. Plus, there is a wide range of performance. Blazer and Prvi Partizan are lower power rounds. Buffalo Bore and Silvertips are higher power.

      The problem with 10MM’s use as in defense is perhaps only that the latest, greatest defensive JHP ammo is often not available in 10MM loadings. Here I refer to Federal HST, Remington Golden Saber, etc.

      • Uncle Siam

        Yes and no. You can still hand load any JHP bullet that is available for the 40s&w.

        I’d personally do a weaker load for control ability and noise reduction. You can always load a full powered 10mm at the end of the clip if you need it, or in the extra magazine and just swap it.

  • Hedd Wyn

    If you want to shoot lead bullets through a G20 just buy an aftermarket barrel from someone like lonewolf

  • Django

    I own both the 3rd gen. and 4th gen to be honest the recoil is the same. As far as ammo Underwood ammo in 135 grain is a pleasure to shoot, as is their 155 gr bullet. As far as economy and plinking, Armscor is very good! The G20 is an awesome gun the recoil is over-hyped, try it you will love it. They are very accurate due to the 10 mm’s flat trajectory and they hit like a monster! I do not see why this cannot bean everyday carry gun.

  • TFlorida2


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