The Gen 5 Glock 21 MOS handgun is possibly the most reliable .45 ACP on the market, which is no surprise coming from Glock. But does that make it a good self-defense handgun? In my opinion, yes, it does.
I drifted away from .45 caliber handguns years ago due to ammo capacity, cost, and felt recoil compared to 9mm. But I’ve slowly been moving back, and while my love for the 1911 plays a role, the Gen 5 Glock 21 is probably the biggest reason.
The Evolution of Glock and the .45 ACP
Glock’s journey from an Austrian curtain rod manufacturer to one of the world’s most recognized handgun brands is nothing short of legendary. When Gaston Glock designed his first handgun for the Austrian military in 1982, few could have predicted the global success that would follow.
Today, Glock is a household name, trusted by law enforcement, military units, and civilians. Known for reliability, simplicity, and innovation, Glock sets the gold standard in polymer-framed pistols.
My Experience with the Glock 21
I never shot a Glock pistol until my police academy days. Back then, it was just becoming a brand associated with quality and reliability. Many initially dismissed Glocks as “plastic” guns, but their performance quickly silenced critics.
As law enforcement pushed for a more modern handgun in the late ‘80s, Glock became the cornerstone of duty pistols. This article isn’t a history lesson on Glock, but it’s important to recognize the brand’s reliability across multiple calibers.
Reliability in a .45 ACP
The gun world took a big swing away from larger calibers, embracing the 9mm round with open arms. For the most part, 9mm handguns have remained dominant, with the Glock 19 and Glock 17 leading the way.
But in recent years, however, the .45 ACP and even 10mm have seen a resurgence in popularity. I won’t get into the debate over caliber choice, but I will share why I like the .45 ACP for specific purposes.
Before that, let’s take a look at the Gen 5 Glock 21 MOS, which has been on the market for a couple of years now.
Glock 21 Gen 5 MOS: Two years later
I think the Gen 5 update was one of the best updates Glock has made in a long time. Going from 3 to 4 was a big improvement, but the Gen 5 update was even better.
Seeing the release of a Gen 5 MOS version of the Glock 21 was exciting because I had been looking for one. My plan was to set up a Glock 21 for self-defense — specifically home defense.
I typically wait a while after a new gun is released to see if any issues arise. Not that I doubted Glock, but I waited anyway.
Now, nearly two years later, I think it’s safe to say the Gen 5 MOS version is living up to Glock’s reputation.
Glock 21 Gen 5 MOS Features
- nDLC Surface Finish: Provides a hardened, rust-resistant finish. In my experience, Glock’s finish is tougher than many competitors.
- High Traction Gen 5 Frame Texture: I like the texturing Glock did on the Gen 5 models but would love to see something even more aggressive.
- Marksman Barrel: It’s hard to beat the accuracy of a stock Glock pistol. For an out-of-the-box gun, Glock handguns are accurate, and the barrels are durable as well.
- MOS (Modular Optic System): A great addition that allows for easy optic mounting. Honestly, I don’t see why Glock continues to make models without MOS.
How the Glock 21 Handles .45 ACP Recoil
While I’ve shot the Glock 21 multiple times at shooting events, I hadn’t put it through extensive testing until now. But now that I have one, I’ve been doing some plinking and a few drills with it and so far, I haven’t had a single malfunction.
The recoil isn’t bad for a .45 ACP. AmmoToGo.com provided some Federal 230 grain FMJ, 230 grain Seller & Bellet JHP, and some 230 grain +P Federal LE Tactical HST ammo for the review. The difference in recoil with the +P rounds was noticeable but still controllable.
Glock 21 Gen 5 MOS Specs
- Caliber: .45 ACP
- Capacity: 13+1 rounds
- Barrel Length: 4.61 inches
- Overall Length: 7.95 inches
- Width: 1.34 inches
- Weight: (unloaded): 29.30 ounces
- Finish: nDLC
- Trigger Pull: ~5.5 lbs
- Sights: Glock factory sights and optics-ready plate
Is it Good for Self-Defense?
When considering the Glock 21 Gen 5 MOS for self-defense, it’s important to weigh the pros and cons. While the 9mm vs. .45 ACP debate will never end, I prefer .45 ACP in some cases.
In my law enforcement career, I’ve seen many incidents where a 9mm round fired inside a home traveled through multiple walls. A good JHP round helps, but 9mm is fast and penetrates deeply. That’s one reason I prefer .45 ACP for home defense — it reduces the risk of over-penetration.
The other reason is simple: a bigger bullet creates a bigger wound. Don’t get me wrong, I’m not against 9mm ammo for self-defense. Most of my handguns are 9mm, and I carried one for years at work.
Because the Gen 5 Glock 21 MOS holds 13 + 1 and has a manageable recoil, I think it would make a great self-defense handgun. I’m not against carrying it in a good OWB concealable holster during the winter months.
So, deciding weather or not a .45 ACP is right for you simply depends on your preferences in a self-defense handgun.
Best Accessories for the Glock 21 Gen 5 MOS
Because this is a new project of mine, I’ve started selecting accessories for the Glock 21 MOS.
Trijicon RMR Type 2
There are a lot of good options for optics, but because of the .45 ACP recoil, I’m going to use a Trijicon RMR for my optic. At some point down the road, I’ll upgrade the iron sights so they can be used with the optic installed.
One thing I love about Glock is their MOS system makes finding the correct mounting plate easy. This makes for a simple process of mounting any optic you want. Some of my Glock handguns came with multiple adaptor plates, but you can also purchase induvial ones or a set.
As you can see from the MOS guide above, I need the 06-size mounting plate for a Trijicon optic in a caliber other than 9mm. My Glock 21 MOS came with the 06 plate, so it worked out great.
Nightstick TWM-30 Weapon Light
Just like with optics, there are plenty of good weapon-mounted lights to choose from. For this setup, I decided to use the Nightstick TWM-30. It’s a 1200-lumen light that will light up an entire room quickly. I also have the TWM-30T Turbo light, but it does best for longer distances. Because this set up will primarily be used in doors, I want something with a wider beam.
Other solid options include the Streamlight TLR-1HL or the Surefire X300. The Glock 21’s size allows for full-size WMLs without issue.
Holsters
Find the right holster is often the hardest task because there are either too many options or not enough. Because of the Glock 21’s size, I prefer a concealable OWB holster like the Safariland 7378RDS-7TS ALS. Unfortunately, options are still limited. Hopefully, we’ll see more holster choices for the Glock 21 MOS soon.
The perfect home defense handgun for me
If you look for the perfect caliber, you will never find it. No one agrees on anything, especially in the gun world. I like 9mm, and I even have a few 10mm firearms. But there is nothing wrong with a reliable .45 ACP either.
This somewhat new Gen 5, Glock 21 MOS will make a great defensive handgun and for me, it’s a perfect home defense option. So, if you’re a .45 ACP fan, check out Glock’s newest MOS model.
