Although Glock’s lineup of handguns features mostly impressive firepower – enough to get the job done in so many instances – some law enforcement officials in the late 1990’s-early 2000’s found that Glock’s standard issue 9×19 pistols, such as the Glock 17, 19, 26, or 43, were not adequately taking down criminals. This led to a bit of a conundrum on the part of Glock, in that the company was faced with the decision to either concede that its existing handgun line wasn’t up to par for some officers and develop/adopt a new caliber, or ignore the pleas for a more powerful Glock. Glock settled on the former, and the result we ended up with is the Glock 37, a .45 G.A.P. (Glock Automatic Pistol) using cartridge developed to match the power of the .45 Auto guns while maintaining a compact form factor and high ease of use.

The .45 GAP, while offering the same power as the .45 ACP, is made shorter in order to fit a compact handgun. This is because Glock had no intention of drawing a contrast between the G37 and their other, more compact handguns, or invite comparisons to the .45 Auto Glock models – the 21, 30, and 36. The Glock 37 was a monumental achievement in that Glock continued to combine impressive stopping power and compact form, this time on an even greater level – it’s not tough to see why the New York State Police Department adopted the gun shortly after its introduction to the market. You’ll understand the greatness of the Glock 37 as well after reading this, our Glock 37 Gen 4 Review!

Glock 37 Specs

Caliber / System

  • .45 G.A.P.


  • Length: 204 mm / 8.03 in.
  • Height: 140 mm / 5.51 in.
  • Width: 30.00 mm / 1.18 in.
  • Barrel Height: 32 mm / 5.51 in.
  • Length Between Sights: 165 mm / 6.49 in.
  • Barrel Length: 114 mm / 4.48 in.


  • Unloaded: 820 g / 28.95 oz.
  • Loaded: 1005 g / 35.48 oz.

Trigger Pull / Travel

  • Trigger Pull: ~2.5 kg / ~5.5 lbs.
  • Trigger Travel: ~12.5 mm / ~0.49 in.

Barrel Rifling / Length of Twist

  • Barrel Rifling: right hand, octagonal
  • Length of Twist: 400 mm / 15.75 in.

Magazine Capacity

  • Standard: 10

Glock 37 Build

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Glock 37 Backstraps

As previously stated, the thought behind the Glock 37 was to develop a firearm which could accommodate .45 ACP-like cartridges without compromising in form factor. In order to achieve this, Glock’s special .45 GAP cartridge is shorter than the traditional .45 ACP, but slightly shorter, and uses a small pistol primer. The G37 uses the same frame as the 9 x 19 Glock pistols, but uses a wider sight to accommodate the larger diameter of the .45 GAP, and the magazines are the same dimensions as those used in the 9 x 19 Glock’s. In typical Glock fashion, the G37 is composed mostly of the patented Glock polymer-blend, which makes for a tough, durable, resilient, and long-lasting gun. As we are reviewing the Gen 4 version of the Glock 37, we should note that all of the typical Gen 4 bells and whistles are included – the modular back straps, the enlarged and reversible magazine catch, dual recoil spring assembly, and the new and improved textured grip. Already known for their build quality, the dual recoil spring assembly in particular ensures an even longer-lasting Glock – for me personally, the G37 has held up over the course of two years nearly perfectly.

Glock 37 Shooting

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Glock 37 In Action

The selling point of the Glock 37 is in the caliber and stopping power of the firearm, which means that this section of our review is the most pivotal. I can confidently state that after extensive G37 use, I can conclude that it is one of the most well-balanced handguns I’ve ever had the pleasure of using. Although the 37 is somewhat more difficult to handle than its siblings in the Glock family (as is to be expected, given the larger caliber), it is still plenty accessible for novices as well as experienced gun owners. Accuracy when shooting is as good as can be expected – I performed similarly with the .45 as I did with guns of different brands and lesser calibers, leaving two-inch groups at roughly 25 yards. The gun is comfortable to hold (and highly customizable for those who do not find the factory grips agreeable), and immediately launches itself to the head of the pack of the .45 Auto ‘family’ – this is most unsurprising, given that Glock seems to accomplish this feat in every gun market niche it enters.

Glock 37 Magazine

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Glock 37 Magazine

The standard capacity of the Glock 37 magazine is 10, with the option for a +1 magazine extension which protrudes from the mag well just a little, compromising on form factor slightly. Again, the Gen 4 version of the Glock 37 has a handy, enlarged magazine release and well which is also reversible. This makes for a hell of an easy experience in terms of loading and ejecting magazines, allowing users to switch the catch to the left or right side of the handgun. Not unlike other handguns, the 10-rounds of GAP will either be enough to satisfy your gun needs, or they won’t: I know some folks who couldn’t live without the capacity of 17 in the Glock 17’s, while I personally am just fine with 10. Figure out what it is that you need out of your handgun, and adjust accordingly. Just recognize that the laws of nature dictate that a higher caliber handgun either be larger in size or feature a (relatively) smaller magazine to accommodate the rounds.

Glock 37 Sights

Oh yes, it’s that time of the review again. Time to lament the shortcomings in the Glock factory sights before cheerfully reminding you that, being a Glock gun, the G37 sights can be swapped for a variety of different new and improved sights! Until Glock does something about their underwhelming sights, we will continue to accurately label them as one of the few shortcomings in an otherwise extremely pleasing gun formula. In the meantime, you can either buy a new set of sights, or make do with the front dot and rear “u” marked sights on the Glock 37 – they’re not great, but they’re not terrible either.

Glock 37 Conversion

I’ve seen a number of people in various places ask about conversion options shortly after purchasing the Glock 37. The problem that some people encounter here is that they purchase the Glock 37 thinking that it will accept .45 ACP ammunition without realizing that, as described, the .45 GAP is a specially-made cartridge and that the Glock 37 is not compatible with .45 ACP rounds. I’m just going to state this now to make it perfectly clear: The Glock 37 cannot be converted in any safe or official capacity, and the Glock 37 only accepts the ammunition that was made for the Glock 37. This is a sad reality to accept given the wealth of options that are available in ammunition in other Glock pistols, but it is a reality that people need to accept nonetheless. This is a result of Glock manufacturing a firearm that accepts its own unique cartridge. Therefore, if you’re perhaps interested in purchasing a Glock 37, I cannot recommend giving the gun a try before purchasing highly enough. Appreciating and enjoying the .45 GAP cartridge is imperative for would-be 37 owners – it is essentially a pre-requisite. Try the gun before purchasing it and you won’t have to worry about trying to convert the gun at some later point – you’ll know it’s not the gun for you.

Glock 37 Safety and Assembly

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Glock Safe-Action System

Given the fact that the Glock 37 was developed thanks in large part to safety concerns of law enforcement officials, it’s only fitting that the G37 itself have good safety features – which it does, in spades. Like the other Gen 4 Glock guns, the G37 takes advantage of Glock’s three-point “Safe Action System” – a three-part safety system designed to negate the most common risks associated with handguns. This includes, for starters, the Glock trigger safety – a level built into the trigger of the gun that needs to be engaged simultaneously with the trigger in order for the trigger to fire. The spring-loaded firing pin safety ensures that the firing pin is blocked from moving forward unless the trigger is being pulled. Finally, the drop safety of the gun ensures that no unwanted firing takes place in the event of an accidental drop. In addition to these features, the superior build of the G37 is an insurance policy in itself against any unsafe results from general handgun degeneration, wear, tear, and aging. You won’t find a safer.45 handgun than the G37.

Glock 37 Accessories

Unlike the unfortunate ammunition limitations which were described earlier, the Glock 37 has an overwhelming number of accessory and customization options for their owners. From grips, to slide back platers, to recoil springs, to holsters, to sights, there are a number of ways to improve and alter your Glock 37 in order to help make your G37 experience a more accessible one. Here are our Top-5 Glock 37 Accessories:

1. Talon Grips

37 aA single-piece wrap around adhesive grip, these Talon grips create a more easily grip-able surface of the gun which make a safe, comfortable firing experience even safer and more comfortable. Available in both rubber and granulated texture and just 0.5 mm thick, these grips manage to maintain the slip and easy to hold build of the gun while only enhancing grip-ability (all of the good, none of the bad). I used these grips for the Glock 17 and 19, as well as for the Glock 37, and I have to say that the increase in comfort when shooting made a tremendous amount of difference – the Glock 37 factory grips are quality, but the Talon’s are over-the-top great.

2. Trijicon HD Night Sights

37 bAfter covering the less-than-stellar sights included on the Glock 37, you didn’t think we’d let you finish the review without recommending an excellent replacement pair, did you? Trijicon knows sights as well as anyone, and night sights in particular – night sights like the Trijicon HD Night Sight Set for Glock Pistols. Featuring a highly visible colored front sight post with glow-in-the-dark paint, these Trijicon sights are excellent for target acquisition in home defense situation in particular. Easy to install, the subdued, u-notch rear sight and front post can totally enhance the Glock 37 experience – make these your go-to Glock sights!

3. Black Rear Cover Slade Back Plate

37 cFor those who find Glock guns to be a little stale or stiff in terms of their look or aesthetic, there are always swappable back plates. An easy and simple way to personalize your Glock 37, back plates are easily installed, affordable, and varied enough to find the perfect fit for you (you could even design your own with an online tutorial). NDZ Performance in particular makes a good set.

4. Stainless Steel Competition Recoil Spring

37 9Looking for different weights in your gun than a Glock 37 provides? You’re in luck. You can actually tune the spring to your specific shooting level, skill, and needs by using drop-in, stainless steel guide rods made by Glock. Available in 5 different weights, these are a great option for gun owners who are not feeling that the G37 is optimal for their shooting profile.

5. BlueFire 2-in-1 Flashlight and Laser Sight

37 eThe Glock 37 is a great option for home defense and self-defense purposes, but that doesn’t mean that the G37 defense experience can’t be made even better. Night sights will help with target acquisition at night and in low-light situations, but when targets and areas need to be better illuminated, lights and laser sights are a great option. BlueFire makes an excellent 2-in-1 combo that gets the job done for anyone who wants to be extra cautious with the defense firearm.

Glock 37 Holsters

37 7Glock guns are some of the most popular guns for open and concealed carrying in the world, and it’s no surprise as to why – the compact form of Glock guns make them easy and downright comfortable to carry. For the sake of safety, and increased comfort, though, carrying your Glock in a holster is the way to go. There are a number of great holster options for the Glock 37, and I personally recommend the Fobus Roto Holster or the Blackhawk 410513CT-R, which are two proven crowd pleasers. It’s always best, however, to find the Glock 37 holster that you find most comfortable and safe.


The Glock 37 is a revolutionary weapon that took the stopping power of the .45 ACP, put it in a compact handgun, and managed to keep the firing and controllability to a reasonable level. Is the Glock 37 a perfect handgun, without limitations? Definitely not. For those of you who want .45 ACP-level shooting in a compact handgun, however, and in the world-class build of a Glock, the G37 is as good of a choice as you’re going to get. Try the Glock 37 out at your local range today to see if it works for you!

Thanks for reading our Glock 37 review – check back for more on Glock guns here at Gunivore!

Nate M.


  1. Wondering if anyone can comment on how the Glock 37 handles 230 grain GAP ammo. I don’t believe it was originally offered when the GAP cartridge was created. Now that it is, I’m wondering if the Glock 37 can handle it. One article I read indicated the 230 grain GAP ammo pushes the Glock 37 to it’s structural limits… have any Glock 37’s broken as a result of running that ammo? Does anyone here have experience running 230 grain GAP ammo through the Glock 37? If so, how many rounds of it have you fired through your 37? I think the 45 GAP is a great idea. Carried a Glock 19 for years, and wished Glock would make a handgun that carried a 45, but in the smaller form factor of the Glock 17 / 19. In addition to wondering if the G37 can handle 230 grain GAP ammo, I’m also wondering what GEN updates the clock has done for the 45 GAP family of handguns. I read that the G37 was upgraded to GEN 4, but apparently not GEN 5. Also read that the G38 and G39 never got updated to GEN 4. Is that true?

    1. The G37 handles 230grain quite well actually and shouldn’t give you any problems as long as you don’t try to cut corners with handloading or anything like that. We used a bunch of different ammo, but we liked the Winchester SXT. We can’t speak to how it will affect the longevity of your gun, but it shouldn’t present any performance issues. Regarding the new gen Glocks, they never made a gen 4 or 5 .45GAP pistol, but we’re not sure why.

    2. I own a Glock 37 Gen 1 and used 250 rounds of the Speer Lawman 230gr for target practice. The only problem I have had is the magazine wear that rechambers a round after the last round has fired and leaves the gun breached open.

  2. I purchased my Glock 37 Gen 3 two weeks ago. It is a retired state police weapon, and is in excellent condition. Yesterday was my second range trip with this Glock, and I must say how impressed I am with the handgun and the cartridge. I found it to be very controllable, inherently accurate, and as with any Glock, a breeze to disassemble and clean. Ammunition seems plentiful, as both of the gun shops in my area have ample supplies of both practice and defence ammunition in both 185 and 200 grain. I am quite pleased with my purchase, and look forward to purchasing several more as I come across them.

    To all the naysayers who seem to be determined to condemn this weapon and caliber, I would suggest actually picking one up and trying it out personally before continuing with the borderline hysterical diatribes I have seen on some of the forums regarding both weapon and caliber… may just be pleasantly surprised…..

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