Glock 45
The Glock 45 shares the same crossover architecture as the Glock 19X—a full-size G17 frame paired with a compact G19 slide—but in standard black with factory MOS (Modular Optic System) availability that makes it the optics-ready version of the crossover concept. With 17+1 capacity, the Gen 5 Marksman barrel, front slide serrations, and the option of a factory-milled optics cut, the G45 has become one of Glock’s most popular configurations for duty, home defense, and competition use where a full grip and red dot capability are both priorities.
Read our full Glock 45 Buying Guide ↓
G45 vs. G19X—Same Config, Different Purpose
The G45 and G19X use identical frame and slide combinations but differ in key ways. The G45 comes in standard black finish; the G19X in coyote tan. The G45 is available in MOS configuration with a factory optics cut; the G19X has no factory optics option. The G19X ships with night sights and a flared magwell from the factory; the G45 uses standard sights. For optics-focused buyers the G45 MOS is the clear choice. For buyers who want the best factory-equipped non-MOS crossover, the G19X’s night sights and flared magwell provide more out-of-the-box value. For most buyers who plan to add a red dot, the G45 MOS is the right starting point.
G45 MOS Configuration
The G45 MOS features a factory-milled slide that accepts standard Glock MOS adapter plates, accommodating Trijicon RMR, Holosun 507c/509t, Leupold DeltaPoint Pro, and other popular red dot footprints. The adapter plate system provides a secure, repeatable mounting solution with no aftermarket milling required. For competitive shooters in USPSA Carry Optics division or for duty and home-defense users who want a factory optics solution on a crossover-configuration Glock, the G45 MOS is among the most practical configurations available. The Gen 5 Marksman barrel provides the accuracy foundation for the red dot to work with.
Front Slide Serrations
The G45 added front slide serrations to the standard Gen 5 feature set, allowing press-checks and administrative slide manipulations from the front of the slide. This is particularly useful for shooters who run suppressor-height sights or a mounted optic that makes rear-seam press-checks awkward. Front serrations have become a common preference among duty and competition shooters who perform frequent press-checks during training and use. The G45’s inclusion of front serrations at standard pricing makes it a minor but meaningful upgrade over standard G17/G19 Gen 5 models that don’t include them.
Competition Use
The G45 MOS has become a popular USPSA Carry Optics platform, combining the full-size grip for better recoil control and magazine capacity with the shorter G19 slide that many shooters find balances better for fast target transitions. The factory Marksman barrel provides good accuracy without aftermarket work. Adding a quality red dot, an aftermarket trigger, and magazine extensions brings the G45 MOS to competitive configuration without gunsmithing. For Production division shooters who want a stock Glock, the standard G45 competes well against the G17 and G34 with its front serrations and crossover ergonomics.
Duty and Home Defense
For duty and home defense use, the G45’s full-size grip with 17-round capacity is the core advantage over the G19. Most professional trainers recommend a full-size pistol for home defense where concealment isn’t required, as the larger grip and longer sight radius improve shootability under stress. The G45 MOS with a quality red dot and weapon light mounted on the accessory rail represents a genuinely complete duty-ready configuration. For law enforcement agencies looking to standardize on an optics-ready crossover Glock, the G45 MOS is the natural choice over the non-MOS G19X.
Where to Go Next
Explore the full Glock lineup on our Glock brand page. For the coyote tan crossover with factory night sights, see our Glock 19X page. For the full-size G17, see our Glock 17 page. Ammunition is available on our 9mm ammo page.