When the US military went about replacing its aging Beretta M9 sidearms, the fight was far from over, with two stalwart rivals dueling it out: Sig Sauer and Glock. Both had a massive following among the military and law enforcement, with loyal customers and sterling reputations. In the end, however, it was Sig Sauer’s P320 that was chosen as the new standard-issue sidearm for nearly all of the military. So what did the P320 do differently, and how did it win out in the military? Here’s a summary of the five top reasons that it beat the rest—and what it means for the soldiers who get to carry it.
5. Cost Savings That Matter
Money matters when you’re purchasing sidearms by the hundreds of thousands. Sig Sauer’s bid came in at $169.5 million—roughly $103 million less than Glock’s proposal. That wasn’t a small sum; it represented a significant savings that could be redirected to other military priorities while still providing a high-quality, reliable pistol.
Government Accountability Office reports the designated list price as “critical” in the final selection. The military bought a high-tech, versatile sidearm without going over budget—a performance and fiscal success, too.
4. In-Aggressive Testing Pitted Sig Ahead
The Modular Handgun System competition wasn’t popularity-contest-fashion—it was dirty, multi-round accuracy, reliability, ergonomics, safety, and high-stress performance testing. In those tests, the P320 dominated Glock again and again.
Sig suggested two configurations: full-size XM17 and subcompact XM18. That modularity created space for commanders to move in, pairing a weapon to a mission. Even when Glock whined about the choices, the GAO embraced Sig’s technical superiority with the operational benefits it provided.
3. Modularity That Makes a Difference
The P320’s modularity is likely its greatest attribute. The system’s central point is a serialized fire control unit, which can potentially be swapped between various grip modules. It enables the very same firearm to shrink, shrink, or reconfigure in seconds so it’s perfectly adapted for patrol, car use, or concealed carry—without needing to purchase a substitute firearm.
For the Army, that adaptability optimized supply, reduced cost, and allowed troops to personalize their sidearm to taste and mission requirements.
2. Safety and Reliability—With Reserve
During testing, the P320 was reliably massive with a 99.8% success rate, supposedly noted. Its break-cleaning trigger and safety features built in ensured its cause of effect.
Certain civilian variants of the P320 have led to news reports of an accidental discharge. Sig contends that the gun has to be consciously drawn to fire, and there have not been any reports of such occurrences on the military M17 and M18 versions, which also feature extra safety mechanisms that the Army demands.
1. General Performance and Long-Term Value
Last but not least, the P320 offered the most well-balanced mix of performance, versatility, and price. Its modularity, battlefield dependability, and mission capability in many missions established it as the gun of today and tomorrow. Being in business with the likes of Winchester only served to enhance its logistics support and supply base. There have been occasional issues, such as recent Air Force testing after one mishap, but the P320 remains the Army, Navy, Marine Corps, and Air Force standard-issue sidearm with over 200,000 in inventory.
The strategic value is self-evident: soldiers now possess an operational sidearm that can be customized to their mission with the benefit of high performance and an acquisition process that balances creativity and fiscal responsibility. Sig Sauer P320 history in the US military continues to linger, but its status as an American small arms legend is secure.