5.7 vs 9mm: Has the 9mm Finally Been Replaced?

When you first start comparing the 9mm and 5.7x28mm, you might think they're radically different. The 9mm looks like a traditional semi-automatic handgun cartridge, and its bullets are significantly heavier.

Conversely, the 5.7mm resembles a miniature semi-auto rifle cartridge. Its bullets are much lighter, and also appear to be more aerodynamic.

Are the two rounds really as different as they seem to be – and if they are, does the newer 5.7 succeed at outperforming the 9mm? Or are the 9mm loyalists (such as myself) correct when they say there’s no real advantage to switching over? Let’s thoroughly compare the rounds and determine the winner of the 5.7 vs. 9mm debate once and for all!

5.7mm vs. 9mm: Differences and Similarities

FN Herstal developed the 5.7 to replace the 9mm: a challenging task. If FN Herstal succeeded, then we should expect the 5.7 to outperform the 9mm in nearly every measurable aspect.

Don't count on the 9mm to go down without a fight, though. There are good reasons why it’s stayed so popular for over 120 years. Convincing its many fans to switch will prove challenging no matter the conclusion of this article.

Cartridge Specs

The 5.7x28mm cartridge is narrower but longer than the 9x19mm Parabellum.

Most 9mm bullets weigh 115, 124, or 147 grains; substantially heavier than the 5.7's usual 27 and 40 grain bullets.

The 5.7's narrower, lighter bullets permit the design of higher-capacity magazines, thus enabling the shooter to carry more rounds.

If you're looking for a small yet powerful round – like many law enforcement and government agencies currently are – then the 5.7 easily wins this matchup.

Recoil

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Neither cartridge is known for having heavy recoil. Fans of the 9mm often argue that this is one significant advantage in the 9mm vs. 44 ACP debate, as follow-up shots tend to be more accurate when there is less recoil.

However, the 9mm has been outdone in terms of recoil. Although it may attain higher muzzle velocities, the 5.7’s lighter bullets and powder charges grant it undeniably lighter felt recoil. I’ve never considered the 9mm to have overbearing recoil, even while firing heavy self-defense loads. Even so, the 5.7 kicks more softly.

Granted, a heavier firearm will produce less recoil, although carrying one around all day can be tiring.

I give the advantage to the 5.7. It generates around one-third less recoil than the 9mm – the latter of which isn’t known for having much recoil in its own right.

Trajectory

Since both rounds are designed for handguns and submachine guns, their trajectories will not be as impressively flat as those belonging to cartridges intended for long-range shooting.

Most shooters prefer a flat trajectory, because it requires fewer calculations and adjustments.

At close range, differences between these rounds' trajectories are minimal. However, the faster bullets of 5.7 ammo exhibit flatter trajectories than the bulkier 9mm rounds as distance to the target increases.

The 9mm was designed to be lethal out to 50 meters. While it is technically lethal beyond that range, the bullet's trajectory doesn't allow it to be effective at long range – even when fired from a carbine.

The 5.7 was developed to effectively pierce body armor at 200 meters. It needs a flat trajectory to be accurate at that distance – the reason why it wins this category.

Accuracy

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Accuracy depends on the shooter's skill level, the gun, the quality of the ammo, recoil, and bullet trajectory.

The more recoil a gun has, the less accurately the average shooter will fire it. This is partly because the shooter will anticipate heavy recoil, thus jerking the trigger instead of steadily squeezing it.

These two rounds’ accuracy will appear very similar over the close ranges they are designed to cover.

However, the 5.7x28mm will begin showing its superior accuracy over longer distances, largely due to its lighter recoil and flatter trajectory.

Stopping Power

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“Stopping power” is an overrated and misunderstood metric for cartridges. It is determined by several factors, including capacity for penetration and wound channel diameter: two variables that are essentially mooted by a single well-placed shot.

The more efficiently a bullet penetrates and the larger the wound channel it inflicts, the more stopping power it is considered to have. A higher-velocity round often achieves better penetration, but not always.

The 5.7 has a higher muzzle velocity. Its bullet is also narrower. These two qualities might have helped it penetrate more effectively than the 9mm if not for one fact: The 5.7 bullet is substantially lighter than the 9mm’s, and reaches its target with considerably less momentum as a result. For this reason, the 9mm bullet generally penetrates better than the 5.7.

The 9mm finally has a win.

9mm vs. 5.7 for Self-Defense

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I don't expect to settle this discussion in this short section, because I know how long the 9 vs. 40 vs. 45 debate has raged. As the 5.7 continues increasing in popularity, I believe it will also be included in debates to determine the best self-defense cartridge.

The 9mm has proven itself to be an effective personal defense cartridge by law enforcement and civilians alike.

Since the 5.7 was designed to replace the 9mm, it should at the very least be equally effective for self-defense. Militaries and law enforcement agencies certainly believe this to be true, as many are issuing the new ammunition to their personnel.

Despite this, the 9mm remains my choice for concealed carry. That’s partly because I’m already so accustomed to it; partly due to the availability of guns and ammo. More options make it much easier to find the gun and ammo that fit you best.

Home Defense

For a home defense round, I choose a 9mm because of the availability of guns and ammo. This means I’ll consistently find firearms and ammunition to restock my supply. The 9mm wins the personal defense weapon section, but this could change as the popularity of the 5.7 caliber increases and more guns and ammo options begin hitting the market.

Ammo Cost & Availability

The 9mm has existed for over a century. Hundreds of manufacturers currently produce the most popular centerfire handgun ammo on the planet. You can familiarize yourself with a few of them on our 9x19mm ammo page.

One downside to 9mm’s popularity is that it becomes one of the first types of ammo to vanish during a shortage. It's also one of the first to come back into stock, however. Availability might be delayed, but not for long.

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For more ammo options, browse our inventory of Remington 9mm ammo, PMC 9mm ammo and Fiocchi 9mm ammo.

Buying in bulk is always smart. Make sure to check out our stock of 9mm bulk ammo, too!

Federal Premium American Eagle 5.7x28mm ammo is more expensive than 9mm ammo by the same brand and label. Five-point-seven ammo is also more challenging to find, even when other ammo is readily available.

The 9mm is the winner of this round thanks to its relative abundance and lower price. This could change as the 5.7 continues to rise in popularity, though it’s difficult to overstate just how much more popular 9mm is at present.

Firearm Options

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Both cartridges are typically chambered in pistols, pistol caliber carbines, submachine guns, with pistols still being the most popular for either.

It's much easier to find a pistol chambered in 9mm than 5.7. Only a select few companies manufacture 5.7 firearms, which ultimately drives up those guns’ price tags.

Whereas 5.7x28mm firearms are priced on the higher end of the spectrum, 9x19mm firearms are available in various price ranges: low, high, and everything in between.

9mm pistol manufacturers include Glock, Smith & Wesson, Ruger, Hi-Point, Kimber, and dozens (if not hundreds) more. Excluding carbines and submachine guns, the majority of 5.7x28mm firearms are FN Five-seveN, Ruger-5.7, and Smith & Wesson M&P 5.7 handguns.

The 9mm wins this section. It's much easier to find a gun chambered for it at a reasonable price.

Ballistics

The team at Ammo.com crafted these incredible ballistics tables for both cartridges. Reference them to compare 9mm ballistics vs. 5.7x28 ballistics.

9mm Ballistics

Note: This information comes from ammo manufacturers. Actual ballistics obtained with your firearm can vary considerably from advertised ballistics. Also, ballistics can vary from lot to lot with the same brand and type of load.

5.7mm Ballistics

Note: This information comes from ammo manufacturers. Actual ballistics obtained with your firearm can vary considerably from advertised ballistics. Also, ballistics can vary from lot to lot with the same brand and type of load.

5.7 Development

NATO requested a replacement for the 9mm in 1989. Kevlar body armor was becoming increasingly effective at stopping the 9x19mm, which is why NATO wanted a pistol cartridge capable of armor penetration. FN Herstal answered their call in 1991 with the release of the 5.7x28.

The 5.7mm has proven itself as the round NATO wanted. While it may take a while for it to replace the beloved 9mm, many government and law enforcement agencies around the globe have already adopted it for use.

5.7x28 muzzle velocities vary. The SS190 30gr bullet’s muzzle velocity is 2,350 fps; the SB193 55gr bullet, 1,000 ps. Muzzle energy for the 5.7 typically ranges from 120 to 394 foot-pounds.

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9mm Development

Georg Luger designed the 9mm in 1901. It entered production the following year. The first 9x19mm submachine guns were already adopted for military use by the beginning of WWI due to their ability to penetrate the average soldier's gear.

Popularity of the 9mm would skyrocket during WWII, when it was used by several militaries, police agencies, and civilians. NATO adopted it as its official sidearm cartridge in 1955.

It's only risen in popularity since then, even with the introduction of more rounds like the 5.7x28.

Final Shot: 9mm vs. 5.7

The 5.7x28 may have been intended to replace the 9mm, but it hasn’t supplanted the older round by any measure. The 9x19mm has been a staple for over 100 years, and is here to stay.

However, if any cartridge can replace the 9mm, it's the 5.7x28mm. It offers many of the same benefits the 9mm provided compared to the 45 ACP: namely a higher-capacity magazine, lighter, more accurate bullets, and less recoil.

Even though the 5.7 won a majority of the sections, I don't believe for one second that the 5.7 v 9mm debate is over. I think it's only just begun!

Written by

Wes Littlefield