It might be premature to say that FN Herstal’s 5.7x28mm cartridge (“5.7”) is experiencing a renaissance, but the cartridge has done something that most proprietary-ish, specialized calibers don’t do: Bask in increased popularity decades after its introduction.

Now, in addition to the Five-seveN pistol and the P90, a number of manufacturers have already committed to the 5.7 in the form of AR conversion kits and AR-based sub-gun builds. Most notably and more recently, however, Ruger introduced the Ruger-57, a reasonably priced but comparable pistol to FN’s thousand-dollar Five-seveN handgun.

I predict that more companies may follow Ruger’s lead in the coming years. How did we get here, though? Does 5.7 have any real practical application?

Introduced in the early 90s, the 5.7 shares the same philosophical underpinning as the competing (and less powerful) 4.6x30mm cartridge, which Heckler & Koch developed in conjunction with their new HK PDW (later called the MP7) about a decade later in 1999. These high-speed, low-weight calibers were created in response to NATO’s lengthy teasing of a potential replacement of the old reliable 9x19mm round. NATO specifically demanded that the round to dethrone 9mm must have greater range than 9mm, with the ability to defeat body armor, and with a capacity of at least 20 rounds in sidearm format.

FN’s response was the 5.7.

The 5.7 was promising. Pulling charts from Nathaniel F.’s discussion of the 4.6mm in 2016, you can make several objective conclusions about the 5.7 against the 9mm:

5.7 versus 9mm versus 4.6

5.7 versus 9mm versus 4.6: Velocity

5.7 versus 9mm versus 4.6

5.7 versus 9mm versus 4.6: Range

With nearly double the muzzle velocity of 9mm, the 5.7mm has a much greater range than 9mm. The 5.7 is also said to be 30% lighter recoiling than 9mm, and you can achieve 20 rounds of capacity in a full-size frame. Sounds good – right? And as NATO testers concluded in their evaluation of the 5.7 against the 4.6, the 5.7 is the better performer of those two.  Moreover – interestingly – the Global Defence article cited below points out that 5.7 is easy to make:

The 5.7x28mm is close to the 5.56mm NATO calibre both by its design and manufacturing process. It can therefore be manufactured easily on the same production lines as the 5.56mm.

Sharing a common manufacturing process with one of the most popular rounds in the world certainly lends itself to proliferation.

However, there are drawbacks. As Nathaniel concluded in his article:

Overall, the 4.6x30mm suffers the same problems that the 5.7x28mm does, those being poor energy retention and mediocre wounding capability. However, the 4.6mm does improve on the retained specific energy (energy divided by frontal area, an important consideration for armor penetration) vs. the 5.7x28mm. Therefore, I would expect the 4.6mm to be the superior armor defeater, with the 5.7mm having less poor terminal effects.

Even with the extreme velocity advantage over the 9mm, the 5.7 delivers much less energy. It’s pretty easy to do the energy math ourselves without even consulting the energy chart below. The 5.7 moves twice as fast as 9mm, but only is around a quarter of the weight. Therefore, it comes as no surprise that the 5.7 generates only about half to two-thirds of the energy:

5.7 versus 9mm versus 4.6

5.7 versus 9mm versus 4.6: Energy

With 9mm considered by many to already be the low-end baseline for personal defense performance, is the half-power 5.7 even worth considering for self-defense? Especially in pistol format, where the advantage offered by increased range is diminished in both application (i.e., a pistol encounter is more likely to be at close range) and theory (i.e., the diminished potential long-range marksmanship from a pistol rather than a shoulder-fired weapon).

Let’s make the argument that 5.7 is, just for fun and for the purposes of this article, as suitable for personal defense as 9mm.

If we wanted to bolster a case that 5.7 is a viable defense round, we could start with this punny line: The 5.7 uses a bottlenecked case, like the .357 SIG, which is theoretically supposed to increase feed reliability. Second, 30% lower felt recoil is going to translate into better accuracy, better shot placement, and faster follow up shots. Third, the 5.7 can squeeze 20 or (as Hop learned in the video above) 21 rounds into a full-size frame for more capacity than 9mm. Fourth, the ability to defeat body armor is a plus – according to FN, the SS190 cartridge type can defeat two stacked Level II vests at 50 yards.  The round will also go through a vest and remain effective – allegedly penetrating 11 inches into ballistic gel after punching through a Kevlar vest. Fifth, we have the advantage of the increased range we discussed above, albeit this is of limited use for the reasons noted.

But most importantly, how is terminal performance? Apparently, comparable. According to an article I found from USCCA, Federal SS197SR 40gr 5.7mm VMAX makes a permanent wound cavity similar to the venerable Winchester Ranger 127gr +P+ round, but penetrates about half an inch further than the 9mm. If that’s true, then perhaps the speed of the 5.7 translates into more “energy dump” into a target, notwithstanding the much-lower-on-paper energy produced versus the 9mm.

There’s a more lukewarm reception of the SS197SR from Shooting the Bull. This gel testing video notes good penetration and some gnarly permanent cavities with tumbling, but poor expansion from all but one of the six rounds fired into gel.

Moving away from gel and paper, there’s empirical evidence suggesting that the 5.7 is effective.  Over forty countries have adopted the 5.7, including the USA at a federal and state level, most notably, the US Secret Service. According to an article from the Dallas News, the Five-seveN is sought after by Mexican drug cartels for its effectiveness, and FN’s pistol can fetch $5,000 on the black market because of its performance, especially against armored targets. And as macabre as it might be, I reluctantly note for purposes of this discussion (and because someone was definitely going to say something about it in the comments anyways if I didn’t) that the 5.7 round was used in the most deadly American on-base shooting of all time, killing 13 and wounding over 30 when an Army major-turned-terrorist used the Five-seveN in an attack against fellow soldiers.

Accordingly, there is theoretical and real-world evidence suggesting that the 5.7 round is effective.

Assuming that the 5.7 increases in popularity, the round selection will, also. According to FN, the “official” designated 5.7 rounds are as follows – note than many of them are restricted:

SS195LF Lead Free: This round features an innovative and lightweight brass jacketed, aluminum-core hollow point bullet.

5.7x28mm Blank Rounds: The blank round incorporates a synthetic projectile with a reduced propellant charge for training purposes. (available by special order only)

5.7x28mm Dummy Rounds: This inert round is available by special order only.

SS190 Duty Round: The duty round incorporates a limited-risk aluminum-core projectile.

L191 Tracer Round: The tracer round incorporates a tracer element in the projectile to allow improved spotting of the bullet path in low-light situations.

SB193 Subsonic Round: The subsonic round is loaded to subsonic muzzle velocity for use with sound suppressed FN P90® firearms.

SS198LF Lead Free Round: LE restricted aluminum-core hollow point duty round with green tip. The lead-free primer and projectile have the added benefit of making it comply with agency or indoor ranges that might prohibit lead use.

SS197SR Sporting Round: This sporting round incorporates a conventional jacketed lead-core projectile with polymer tip. Exclusively distributed by Federal Cartridge Company in the U.S.

While the SS190 duty round and its armor-rending capabilities are currently restricted to LE/military only, according to our partner for this article, Ammunition To Go, there are presently three civilian-available varieties.  Note that these rounds may still be effective against armor according to the tests I’ve seen, albeit not to the extent that SS190 is.

Commercially, the FN 5.7×28 is available in several varieties. SS195LF lead-free hollow-points deliver velocities over 2,300 feet per second, generate over 340 foot pounds of energy and are completely lead-free (even the primers contain no lead to vaporize), making them ideal for use at indoor ranges. AE5728A total metal jackets (TMJ) utilize a 40 grain lead bullet, completely surrounded in copper, to produce over 320 foot pounds of energy at 1900 fps. Finally, the SS197SR sporting round propels a blue polymer-tipped Hornady V-Max bullet at 1950 fps. With a proven, expanding bullet design and 340 foot pounds of energy, the 5.7x28mm sporting round is the all-around choice for hunting and personal defense.


TFB’S ROUND TABLE IS BROUGHT TO YOU BY AMMOTOGO.COM

https://www.ammunitiontogo.com/product_info.php/pName/50rds-57-federal-american-eagle-40gr-tmj-ammo

50rds - 5.7 Federal American Eagle 40gr. TMJ Ammo

The American Eagle AE5728A would be the go-to for practice on the range. It’s roughly double the price of 9mm, but at 40 cents a round, still reasonably affordable. We can expect those prices to go down if the 5.7 continues to increase in popularity and competition for practice ammo commensurately widens.

https://www.ammunitiontogo.com/product_info.php/pName/50rds-57-fn-ss197sr-40gr-hornady-vmax-polymer-tip-ammo

50rds - 5.7 FN SS197SR 40gr. Hornady V-Max Polymer Tip Ammo

The SS197SR appears to be the favored choice for self-defense. Per the USCCA article referenced above and forum posts I’ve dug up, it does perform similarly in gel to 9mm self-defense loadings, but with more capacity and less recoil. At sixty cents a round, it is, in fact, less expensive than most 9mm defense-oriented hollow points.

https://www.ammunitiontogo.com/product_info.php/pName/50rds-57x28mm-fn-ss915lf-27gr-hollow-point-ammo

50rds - 5.7x28mm FN SS915LF 27gr. Hollow Point Ammo

Finally, the SS195LF pushes rifle-like speeds of 2,300 fps – but using a teensy 27gr bullet. This possibly could lead to overpenetration, and it seems that at 60 cents a round, this might be more suited to the well-heeled shooter who can afford this totally lead-free ammo for practice.


Tell us what you think – is 5.7mm an effective self-defense round? Will we see more 5.7mm pistols in the near future?


Citations:

https://www.ammunitiontogo.com/index.php/cName/pistol-ammo-fn-57

https://fnamerica.com/ammunition-5-7x28mm/

https://web.archive.org/web/20061016074936/http://www.global-defence.com/2006/Utilities/article.php?id=40

Gourley, S.; Kemp, I (November 26, 2003). “The Duellists”. Jane’s Defence Weekly (ISSN 0265-3818), Volume 40 Issue 21, pp 26–28.

https://www.usconcealedcarry.com/blog/fns-five-seven-pistol-self-defense/