The 5.7x28mm has had an odd and unpredictable rise in popularity in the last five years or so. It used to be that only the FN Five-SeveN pistol and PS90 chambered the cartridge, but in short order, half a dozen different handguns chambered the 5.7mm round. We now have a mix of premium, mid-tier, and even budget-priced 5.7 handguns on the market.
I recently obtained a PSA Rock in 5.7mm and it’s been an eye opening experience. It’s the first time I’ve shot a 5.7x28mm handgun extensively. After a few hundred rounds downrange I’ve begun to see why people like the 5.7.
That led me to ask: Is the 5.7x28mm a viable defensive round? Can it outperform any of the established cartridges? What are its pros and cons?
What Is the 5.7x28mm Cartridge?
The 5.7x28mm cartridge appeared in the early 1990s. NATO wanted a Personal Defense Weapon for troops who weren’t fighting on the frontlines. The idea was to produce a weapon that was easier to carry than a full-sized rifle but more effective than a pistol. It also needed to be able to punch through soft armor.
This meant they developed a submachine-gun-sized weapon firing a cartridge that outperformed pistol calibers. FN met the demand with the P90 and the 5.7x28mm round. Alongside it, they released the FN Five-SeveN pistol. The little 5.7 round looks identical to a mini rifle round with its micro-sized projectile, long case, and bottleneck design.
The P90 originally won, but competitors protested, and then the Global War on Terror jumped off and everyone forgot about the PDW concept. The 5.7x28mm round saw success globally with military and police forces alongside the P90, including the U.S. Secret Service.
The cartridge languished a bit on the average Joe market until recently, with the rise of numerous handguns and rifles chambering it.
Should you use the 5.7x28mm for Self-Defense?
Today, we are going to focus on 5.7mm handguns. Rifles are a different subject and a different debate. Should you use the 5.7 round for self-defense in a handgun? That will be a decision you have to make, but I can provide a bit of data around the idea.
Some older data, along with autopsy reports, showed the round underperforming. But that data was based on the SS190 armor-piercing variant. Armor-piercing rounds generally perform poorly in soft targets, and the SS190 isn’t widely available to civilian users anyway.
Sadly, real-world data is scarce. Finding after-action reports from law enforcement and military forces simply isn’t happening. The best data we have comes from the Ft. Hood tragedy in 2009, where a 5.7 pistol was used. From that tragedy, we can gather that the round is effective when it hits the torso.
Times and ammo have changed. The FN-produced SS197SR loaded with a Hornady V-MAX blue-tip projectile performs extremely well. This projectile penetrates deeply and expands sufficiently.
Speer also produced a Gold Dot variant of the 5.7 round. Gold Dot is a proven performer in other calibers, and this version shows expansion up to .35 inches, which is the size of an unexpanded 9mm round.
Lucky Gunner did a ton of gel testing with the various 5.7 cartridges and showed that with the right round the cartridge can penetrate to adequate depths and expand impressively through a handgun.
Penetration and Projectile Size
Penetration is the most important factor in choosing a defensive handgun round. Second is projectile size up to a point. The projectile needs to penetrate deep enough to hit vitals and disrupt them.
This is where the 5.7x28mm gets criticism. People don’t believe it’s capable of striking those vitals. We don’t have much data on what the 5.7 does and can do to the vitals, but we do know it can reach those vitals.
Pros of Using a 5.7mm Handgun for Self-Defense
Penetration and expansion are critical, and the 5.7 can reach those depths, but choosing a defensive firearm is more than that. A 5.7×28 mm pistol has a few advantages that bear mentioning.
Low Recoil
The little guns have hardly any recoil. They are flat-shooting guns that are easy to shoot rapidly. The 5.7 round won’t hurt your wrists, and it’s tough to lose control over it. It handles more like a rimfire round than a centerfire round.
Reliable Ignition
Unlike a rimfire cartridge, the 5.7x28mm round will reliably ignite and fire due to its centerfire design.
High Magazine Capacity
Full-sized 5.7 pistols typically hold 20 to 23 rounds in flush-fitting magazines. With an extension, the FN Five-seveN can hold up to 30. That’s a lot of ammo, and more is always better.
Accurate
The round is easy to shoot accurately. Accuracy will always come down to the shooter, but this round makes shooting easy. Putting 20 rounds into a 2-inch circle at 15 yards is just easy.
Great Range
As a person who lives rurally, my self-defense scenario can include extended ranges, primarily with animals like coyotes and hogs. The 5.7mm offers flat-shooting performance at extended ranges, making it easy to shoot at 50 yards.
Cons of Using the 5.7x28mm for Self-Defense
Free lunch? Sorry, it doesn’t exist. Here are a few downsides to the 5.7.
High Ammo Cost
5.7 will cost a small fortune to stockpile. It’s a pricey round, and a cheap load is at least .40 cents per round.
Larger Guns with Wider Grips
A 5.7 handgun requires a fairly long barrel to achieve the velocity needed to send those tiny rounds deep into soft targets. This means we are getting at least a 4.5-inch barrel. The cartridge itself is also long, so grips tend to be wide front to back.
It’s Loud
When you fire 5.7 from a handgun, it’s loud. All guns are loud, but this one is exceptionally loud, which means more hearing loss when used indoors in an emergency.
When Does a 5.7x28mm Handgun Make Sense?
The 5.7x28mm pistol works quite well if you have a recoil-sensitive shooter who wants a reliable, modern gun for home defense. t’s too large for easy concealed carry, but it’s a step up from the .22 Magnum—it shoots faster, penetrates deeper, expands wider, and is more dependable.
It could also make a decent field pistol—something you keep on hand for a wide range of outdoor tasks, including self-defense.
Ammo prices need to drop significantly before the 5.7 will take off. It has the potential to be great and could be a capable defensive cartridge. We need more data on its effectiveness and cheaper ammo for it to succeed.
