The Glock 48 MOS is a Glock 19 that went on a diet. That’s the short version, and it’s mostly accurate. The G48 gives you roughly the length and height of America’s most popular carry pistol in a frame just 1.10 inches wide. The MOS version adds a factory optic cut and a slim accessory rail.
For years, the math was simple. Ten rounds. That was the price of admission for the thin grip, and plenty of shooters, myself included, thought it was too high a price for a gun this size. However, Glock finally answered that complaint this spring, and it changes the math on this pistol considerably.
The Slimline Family Grows Up
Glock introduced the G48 alongside the G43X at SHOT Show 2019.
Both guns share the same slim frame.
The 43X uses the short slide from the single-stack G43, while the 48 gets a longer slide and a 4.17-inch barrel.
Think of the G48 as the duty-length member of the Slimline line, built for shooters who want a real sight radius without a fat grip.
The optic-ready versions came next.
Glock announced the G43X and G48 in MOS configuration in 2020, with a factory-milled slide and a slim rail that puts a light close to the bore, just ahead of the trigger guard.
They also added the nDLC finish, a reversible magazine catch, and the Glock Marksman Barrel.
That’s the gun most people buy today, and it is very popular.
The plain-slide G48 still exists.
However, if you’re going to spend the money on a slim 9mm in 2026, I don’t see much reason to buy one that can’t take a red dot.
It just gives you the flexibility to do so, even if you don’t want one now.
By The Numbers
According to Glock’s own spec sheet, the G48 MOS is 7.28 inches long, 5.04 inches tall with the magazine, and 1.10 inches wide.
It weighs 18.31 ounces unloaded and 24.97 ounces with a full 10-round magazine.
The trigger breaks at a listed 24 newtons (about 5.4 pounds), and the sight radius runs just under six inches with the polymer sights.
For comparison, a Glock 19 is about 1.34 inches wide and weighs more than 30 ounces loaded.

Glock 19X image. Image Credit: Author, Corey Ritter.

Glock 19X For U.S. Army. Image Credit: Corey Ritter.

Glock 19X for U.S. Army. Image Credit: Corey Ritter.
You feel that difference on your belt by mid-afternoon.
The optic cut is where you need to pay attention.
The G48 MOS doesn’t use the standard Glock MOS plate system.
The slide is cut for the Shield RMSc footprint, and Glock doesn’t ship adapter plates.
That means you can’t mount dots like the Shield RMSc, Holosun 407K and 507K, or the Sig Romeo Zero directly.
However, check your screws. Gun Digest’s reviewer found that the standard Romeo Zero bolts hit the extractor rod and had to swap to Sig’s shorter 6mm hardware.
Don’t skip that step. Screws that are too long can tie up your gun.
Capacity Was The Biggest Drawback
The 48 always carried a 10-round tax.
Meanwhile, the SIG P365XL and the Springfield Hellcat Pro fit 12 to 15 rounds into similarly sized grips. On paper, the Glock lost that fight every time.

Sig Sauer P365XL. Image: Creative Commons.
The aftermarket tried to fix it first.
Shield Arms opened pre-orders for its all-metal S15 magazine back in 2019, a flush-fitting 15-rounder that sold for $39.99. It worked for a lot of people.
However, reliability reports were mixed, and Gun Digest’s reviewer said as much.
Personally, I’ve never been comfortable betting my life on a carry gun that has reliability issues with the magazine.
Then, in April 2026 at the NRA Annual Meeting in Houston, Glock unveiled its own 15-round metal, double-stack magazines for the G43X and G48. They work in existing pistols.

Image: Creative Commons.
Glock machined a radius into the magazine catch recess so you can keep the standard catch.
No new frame.
No aftermarket mag release.
Safariland’s CADRE team reported that the pistols will ship with them, with standalone magazines to follow.
Fifteen rounds from the factory, in a 1.10-inch-wide grip. That’s the gun Glock should have built in 2019.
Who Should Carry One
Say what you want about Glock’s slow walk on capacity.
That’s beside the point now.
The G48 MOS was always the best-shooting gun in the Slimline family, thanks to the longer slide and sight radius, and it was always easy to carry.
With the right red dot, a factory 15-round magazine, and a decent holster, it does everything a Glock 19 does in a thinner package.

Glock 19 Gen 5. Image Credit: Glock.
It isn’t perfect.
The stock grip texture is slick, the controls are small, and the trigger is merely serviceable.
However, the aftermarket for Glocks is deeper than for anything else on the market, and you can fix every one of those complaints for less than the cost of a decent optic.
If you have smaller hands or carry appendix and the width of a G19 digs into you, this is the one I’d look at first.
It was trying to be a slimmer Glock 19. Now it finally is, with the right capacity.
About the Author: Steve Balestrieri
Steve Balestrieri is a National Security Columnist. He served as a US Army Special Forces NCO and Warrant Officer. In addition to writing on defense, he covers the NFL for PatsFans.com and is a member of the Pro Football Writers of America (PFWA). His work was regularly featured in many military publications.