Glock 47 MOS vs Glock 17 Gen5 (and Where the G45 Fits)

The crossover concept is covered elsewhere on this site. This is the practical call: for a full-size 9mm duty pistol, which of these do you actually pick?

Frame the decision before the model names

Glock's full-size 9mm lineup has grown crowded. The reason it matters to a duty buyer is that the models differ in two ways that have real consequences: how the slide is cut, and what length the slide and barrel are. Everything else, the grip frame, the controls, the magazine capacity, is largely a matter of Glock's shared design language.

Our crossover frames article explains the concept. This piece is the narrower buying question. If you are choosing one full-size 9mm for a belt, do you want the optics-ready Glock 47 MOS or the plain Glock 17 Gen5?

What the two listings say

Read that table as a summary of what the listings describe, not as a full spec sheet. The Glock 47 listing identifies a 4.49-inch barrel, 17+1 capacity and a MOS-cut slide. The G17 Gen5 listing identifies a 17+1 capacity and fixed sights; some SKUs of the G17 ship with 10-round magazines for restricted jurisdictions, so check each listing.

In plain terms, the headline difference is the optic cut. Everything else you might care about, weight, dimensions, sight type and finish details, should be taken from Glock's own spec sheets.

The G17 argument: simplicity and support

The Gen5 G17 is the baseline. It is widely supported by holster makers, accessory vendors and armorers, it is familiar to anyone who has handled a Glock, and it works without an optic. Our full-size G17 review covers what it does well. If your agency forbids slide-mounted optics, or if your officers are not ready to train on a dot, the G17's simplicity is a feature.

The cost is optional upgrade friction. If your agency later moves to dots, the G17 cannot take one without machining, which is real work and a real cost.

The G47 MOS argument: optics from day one

An optics-ready slide is a hedge against where duty pistols are heading. You do not have to mount an optic the day the gun arrives, but the option is built in. That matters if your department is evaluating dots or if you simply want a pistol that will not need a new slide later.

The tradeoffs are not trivial.

• More parts to manage. A MOS slide with plates and an optic is a stack of interfaces to torque and inspect. Our Glock 19 MOS review covers that process.
• Holster complications. An optic changes the holster requirement. Holsters cut for a red dot are a narrower list than plain ones, and light-bearing optic-cut holsters are narrower still. Confirm model compatibility with the holster maker before you commit.
• Plate and footprint choices. You need to pick an optic and a matching plate. GunOptics has a clear explainer on footprints.

Where the G45 fits

The G45 sits in a different place on the spectrum: a full-size grip with a shorter, compact-length slide. That is the right answer for someone who wants a full hand on the grip, the capacity of a full-size magazine, and a shorter barrel for carrying or for a vehicle-heavy role. It is not the right answer for someone who wants maximum sight radius, which is a G17 or a G47 conversation.

If you are drawn to the idea of a pistol that shares parts across sizes, ask Glock how slides and frames interchange across the G17, G19, G45 and G47 families before you rely on it for duty. Interchangeability claims are specific to models and generations, and a mistake on a duty gun matters.

A short decision path

1. Does your policy allow slide-mounted optics? If not, the G17 is simpler.
2. Will it, within the life of the gun? If yes, the MOS cut avoids a later conversion.
3. Is a holster available for the full setup? If not, solve that first.
4. Is there a single-model standard? If yes, match it. Agency policy outranks this article.

Pick this if / pick that if

Transition and training notes

Moving between these pistols is easy at the controls and harder at the sights. The grip, trigger and controls follow the same Glock pattern, so an officer who has trained on a G17 will find a G47 familiar. The difference arrives when an optic goes on: presenting the pistol so the dot appears in the window is a learned skill, and it takes dry-fire and live-fire repetition. Plan training time before you plan the issue date.

If a department is evaluating both, a simple approach is to run the same qualification course with each configuration and let the results, along with armorer feedback, inform the decision. That is a process suggestion, not a claim about what any agency has done.

Also remember backup sights. On an optics-ready pistol, the iron sights still matter, and their height and visibility through the optic window are a configuration choice you make once and then live with.

Bottom line

For most uniformed buyers who expect to run a dot someday, the MOS-cut G47 is the more future-proof pick. For buyers who want the safest, simplest, best-supported full-size 9mm, the G17 Gen5 still wins on simplicity. Neither is a wrong answer; the right one depends on policy and whether an optic is on your horizon.

Check dimensions, weight and sight details on Glock's materials, and verify that your agency approves any pistol before you purchase.

Editorial note: This is an independent editorial overview built from manufacturer specifications and publicly available information. We have not performed hands-on testing of the products discussed, and nothing here is a performance guarantee. Verify specifications, compatibility and legality for your own situation.

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