The 5.7x28mm cartridge has experienced a wave of renewed interest in recent years, with companies like Ruger, Smith & Wesson, and FN developing sleek new handguns chambered for it. It’s easy to see the appeal: high velocity, low recoil, and impressive magazine capacity all come together in a modern package that seems tailor-made for concealed carry and self-defense. But despite all the attention, the 5.7 still hasn’t unseated the reigning king – the 9mm. And when you dig into the details, it becomes clear why that’s not likely to change.
Here are nine major reasons why the 5.7 will never replace the 9mm as the go-to cartridge for self-defense in the United States.
1. Ammo Cost Is Outrageous
If you’ve ever priced out a box of 5.7x28mm, you’ve probably felt a little sticker shock. While 9mm ammo can routinely be found for around $13–$15 for a box of 50 target rounds (and maybe $20–$25 for quality hollow points), 5.7 prices often start at double that – $30 or more for basic range ammo, and $50+ for premium loads. And that’s if you can even find it in stock. Training consistently with 5.7 means digging deep into your wallet every time you hit the range, and for most people, that’s simply not sustainable.
2. Ammo Availability Remains Limited
Even though more manufacturers are jumping into the 5.7 market, the round still suffers from limited availability. Unlike 9mm, which is produced by practically every ammunition company on the planet, 5.7 remains a niche round. Supply chain disruptions or high demand can cause serious droughts. And if you’re relying on a cartridge for self-defense, you need to know that you can walk into nearly any store and find what you need. With 5.7, that peace of mind doesn’t really exist yet.
3. Gun Options Are Still Slim
Sure, the list of 5.7-compatible pistols is growing, with options from FN, Ruger, Diamondback, and now Smith & Wesson. But that list is still dwarfed by the ocean of 9mm pistols on the market. Whether you want a compact carry gun, a duty pistol, a competition setup, or a suppressor-ready model, 9mm has a dozen choices for every one in 5.7. And with gun owners favoring consistency in their platforms, fewer people want to invest in a whole new set of gear just to accommodate one niche cartridge.
4. Compatibility With Existing Gear Is Lacking
One of the biggest overlooked advantages of 9mm is its ecosystem. Many gun owners have carbines, subguns, and pistols that all use the same magazines and ammo. Glock-pattern mags are a prime example, working in everything from pistols to PCCs. With 5.7, there’s very little cross-platform compatibility. If you’re already running a full 9mm loadout, switching to 5.7 means starting from scratch – new mags, new gear, new logistics. That’s a steep price for what amounts to marginal gains.
5. Defensive Loads for 5.7 Are Still Catching Up
Ballistics are a major consideration for self-defense, and while 5.7 does boast impressive velocity, its projectile options still lag behind. The 9mm market has decades of research and development behind it. From bonded hollow points to controlled expansion rounds, you can find dozens of proven 9mm defensive loads backed by law enforcement use and testing. 5.7 just doesn’t have the same track record. Many loads offer minimal expansion and limited energy transfer, especially in short-barreled pistols.
6. Real-World Effectiveness Is Still Unproven
While 5.7 has a reputation for punching through body armor (especially with restricted military/LEO loads), civilian rounds don’t necessarily offer a clear advantage over 9mm in day-to-day defensive use. Real-world data on 5.7’s effectiveness in actual self-defense shootings is scarce. Meanwhile, 9mm has been used in hundreds of thousands of documented incidents – with many agencies and civilians trusting it for decades. That history matters. It brings a level of confidence that 5.7 hasn’t earned yet.
7. Concealed Carry Size and Weight Are a Problem
Despite the slim cartridge profile, most 5.7 pistols are actually larger than their 9mm counterparts. The Smith & Wesson M&P 5.7, for example, is only a few ounces heavier than a comparably sized 9mm pistol, but it’s larger overall – with a longer grip and taller slide. That makes it tougher to conceal for everyday carry. On the flip side, compact 9mm pistols like the Shield Plus or Glock 43X offer solid capacity, manageable recoil, and a much more comfortable carry footprint.
8. There’s No Economical Training Curve
Because of the high ammo cost and limited options, 5.7 is not a round you can afford to practice with in bulk – at least not for most people. Training with a firearm is essential to becoming proficient and confident, especially in a self-defense context. With 9mm, you can easily run through hundreds of rounds in a session without emptying your bank account. Until 5.7 ammo prices drop dramatically and become more consistent, it’s just not a viable long-term training round.
9. It’s Been 35 Years – And It Still Hasn’t Taken Off
Let’s not forget the simple truth: the 5.7x28mm cartridge has been around since 1989. That’s more than three decades of opportunity to challenge 9mm dominance – and yet it still remains niche. Despite some military and law enforcement interest early on, widespread adoption never materialized. Compare that to how quickly .40 S&W exploded in the 1990s or how rapidly 9mm reclaimed dominance in the 2010s, and the difference is clear. If it hasn’t caught fire by now, it probably never will.
Performance Doesn’t Always Equal Practicality
The 5.7 has a lot going for it in terms of performance. It’s fast, flat-shooting, and remarkably light on recoil. For newer shooters or those sensitive to recoil, it can be a joy to shoot. But performance on paper isn’t the same as practicality in real life. When you factor in size, cost, availability, and real-world terminal ballistics, 9mm continues to edge it out in nearly every way that matters for personal protection.
Law Enforcement Isn’t Making the Switch
One of the biggest signs that a cartridge has “made it” is adoption by law enforcement. Agencies have the budgets and testing infrastructure to vet new ammo and weapons, and their choices often influence civilian trends. Yet almost no U.S. police agencies carry 5.7 pistols. 9mm, on the other hand, is trusted by departments nationwide – and with good reason. The training, supply chain, and track record are all locked in. Until 5.7 becomes more than a curiosity, it’s unlikely to earn widespread trust.
Defensive Gun Owners Value Familiarity
Defensive firearm owners often stick with what they know, and for good reason. In high-stress situations, muscle memory, magazine compatibility, and gear consistency matter. Switching to a 5.7 platform means learning a new recoil pattern, adjusting for different controls, and adapting gear setups. For most people already confident with 9mm platforms, the change isn’t worth the hassle.
Cool Doesn’t Mean Capable
Let’s be honest – the 5.7 is cool. There’s something inherently fun about a slick, fast-moving round that feels futuristic and exotic. And the guns chambered for it, like the M&P 5.7 or Ruger 57, are fantastic firearms in their own right. But cool factor alone doesn’t translate into self-defense capability. While 5.7 might be a fun range toy or backup gun, it doesn’t bring enough to the table to dethrone 9mm as the reigning king of practicality.
A Niche Round With a Steep Hill to Climb
There’s no denying that 5.7 has some genuinely impressive attributes – speed, recoil control, and capacity all stand out. But as a serious contender for everyday carry or widespread defensive use, it falls short in too many critical areas. Ammo cost, availability, proven track record, gun selection, and practical concealability all tip the scale in favor of 9mm.
Unless there’s a massive shift in production and public adoption, the 5.7x28mm will likely remain in its lane: a specialized round for niche users. For everyone else, the 9mm still does everything they need – and does it more affordably, more reliably, and with more options than ever before.
Gary’s love for adventure and preparedness stems from his background as a former Army medic. Having served in remote locations around the world, he knows the importance of being ready for any situation, whether in the wilderness or urban environments. Gary’s practical medical expertise blends with his passion for outdoor survival, making him an expert in both emergency medical care and rugged, off-the-grid living. He writes to equip readers with the skills needed to stay safe and resilient in any scenario.