Glock vs Sig Sauer – Which Full-Size 9mm Should You Buy?
Glock vs Sig Sauer – Which Full-Size 9mm Should You Buy?
The Glock vs Sig debate is one of the oldest in the pistol world. To keep it fair, this page compares the two brands’ best-known full-size 9mm pistols: the Glock 17 and the Sig P320-M17.
In simple terms, the Glock 17 is a lighter, simpler pistol with no manual safety, while the P320-M17 is a heavier, modular pistol based on the U.S. Army’s M17 that comes standard with a manual safety.
If you are also choosing ammo for your new pistol, see our Best 9mm Ammo guide or browse more side-by-side pages in our comparison hub.
Quick Verdict
For most buyers:
- Glock 17 is the better choice if you want a lighter full-size pistol with a simple control layout
- Sig P320-M17 is the better choice if you want a manual safety, a modular grip module, and more standard magazines in the box
Winner for most users: Glock 17 — about six ounces lighter than the P320-M17, with a simple layout that is easy to learn.
Glock 17 vs Sig P320-M17 Comparison Table
| Feature | Glock 17 | Sig P320-M17 |
|---|---|---|
| Caliber | 9mm (9x19) | 9mm (9x19) |
| Standard Capacity | 17 rounds | 17 rounds (21 optional) |
| Barrel Length | 4.49 in. | 4.7 in. |
| Overall Length | 7.95 in. | 8.05 in. |
| Height (with magazine) | 5.47 in. | 5.55 in. |
| Weight (empty magazine) | 23.99 oz (Gen6) | 29.98 oz |
| Manual Safety | No | Yes (non-safety model available) |
| Best For | Most full-size 9mm buyers | Buyers who want a manual safety and modularity |
Glock 17 Overview
The Glock 17 is GLOCK’s standard full-size 9mm, with a 4.49-inch barrel and a 17-round standard magazine. It uses GLOCK’s Safe Action System, which has three passive safeties and no manual safety lever.
GLOCK’s current lineup includes the G17 V and the optic-ready G17 Gen6.
Sig P320-M17 Overview
The Sig P320-M17 is SIG SAUER’s commercial version of the U.S. Army’s M17, which SIG says was selected under the Modular Handgun System program. It is a striker-fired 9mm with a coyote PVD stainless steel slide.
SIG says the P320-M17 ships with one 17-round and two 21-round magazines, an optic-cut slide, night sights, and a manual safety. A non-manual-safety version is also available.
Size and Weight
Based on the manufacturers’ published specs, the P320-M17 is slightly longer, taller, and wider than the Glock 17. The biggest gap is weight: about 29.98 ounces versus 23.99 ounces with empty magazines.
Both are full-size pistols. Most buyers use them for home defense, range shooting, or duty-style carry rather than deep concealment.
Safety and Controls
The Glock 17 has no manual safety and relies on GLOCK’s Safe Action System of three passive safeties. SIG says the P320-M17 comes standard with an ambidextrous manual safety.
Neither approach is right for everyone. Choose the setup you will train with, and always follow safe handling practices.
Modularity and Optics
The P320 is built around an interchangeable grip module, which lets you change grip size or frame style. The Glock 17 uses a traditional polymer frame, with backstraps to adjust grip size.
Both are available optic-ready: the P320-M17 from its optic-cut slide, and the Glock 17 in its Gen6 version.
Magazines
Both pistols use 17-round standard magazines, and SIG lists a 21-round magazine as optional for the M17. Glock and Sig magazines are not interchangeable.
Browse options like the Magpul PMAG 17 for Glock 17 or the ETS Omega 17-round magazine for Sig P320. Magazine capacity limits vary by state — always check our ammo and magazine laws guide.
Pros and Cons
Glock 17
Pros:
- About six ounces lighter
- Simple controls with no manual safety
- Optic-ready Gen6 version
Cons:
- No manual safety option
- Fixed frame size
Sig P320-M17
Pros:
- Manual safety standard
- Modular grip module
- Ships with three magazines, per SIG
Cons:
- Heavier than the Glock 17
- Slightly larger overall
Who Should Choose What?
Choose the Glock 17 if you want a lighter full-size 9mm with a simple layout and no manual safety.
Choose the Sig P320-M17 if you want a manual safety, a modular frame, and the same configuration as the Army’s M17.
Final Verdict
The Glock 17 and Sig P320-M17 are close in size and capacity. The choice really comes down to weight, controls, and modularity.
For most buyers, the Glock 17 is the better all-around pick. If you want a manual safety and a modular pistol, the P320-M17 is a great choice.
Continue your research with our Best 9mm Ammo guide, our FMJ vs Hollow Point 9mm comparison, and our comparison hub.
Frequently Asked Questions
Is Glock or Sig better?
Neither is better for every buyer. The Glock 17 is lighter and simpler, while the Sig P320-M17 adds a manual safety and a modular grip.
Is the Sig P320-M17 the same as the Army M17?
SIG says the P320-M17 closely follows the specifications of the U.S. Army’s M17.
Do Glock magazines fit Sig pistols?
No. Glock and Sig pistols use different magazines, so always buy magazines listed for your exact model.
Once you have picked your pistol, browse our Glock holsters and Sig holsters, or stock up in our 9mm ammo category. Buying online? See our how to buy guns online guide.