Thoughts On An Often Misunderstood Caliber, by R.R.

I want to share some information regarding an often misunderstood and maligned caliber, which I recently began learning more about after coming across information on the Fort Hood shooting while studying the ballistics of the shooting.

The FN 57X28mm

What is FN 5.7X28mm? This is a round specifically designed for a class of weapons called PDWs– personal defense weapons. It’s intended for supporting troops to replace their pistols with something half the size of an M16 but with enough capacity and punch to defeat a helmet or soft body armor, and it’s a significant step up from a pistol or even a submachine gun.

The P90 is the perfect example of the PDW concept. It is an ambidextrous bullpup, with a 50-round top loading magazine, minimal recoil, and the ability to spray bullets at an impressive 900 rounds per minute rate of fire (not to say it could fire that many). The standard length military version with a 10” barrel (considered an NFA weapon and a short-barreled rifle) comes in at a mere 20” in length. It’s very concealable under a coat or transportable in a “ready to go” mode in a small brief case or tool box.

A companion pistol, the Five-Seven, was also made, coming with standard 20-round magazines and easily expandable to 30 rounds. A fully loaded pistol weighs as much as an unloaded Glock 17 for comparison purposes, with less recoil and boat tailed .223 caliber bullets that tumble on impact instead of punching straight holes, like pistol bullets tend to do.

What’s interesting about this round? I think it’s obvious that this micro rifle round, which looks like a mini-5.56mm, is specialized and not intended to replace an actual fighting rifle. So in the Fort Hood shooting, Nadal Hasan– a radicalized Islamic Terrorist– wanted to kill lots of U.S. soldiers at Fort Hood. (I actually had family stationed there at the time and remember waiting anxiously until midnight until I heard they were safe.)

Hasan went to his local gun store and asked for the most high-tech handgun they had. In gun store terms, I am sure the clerk thought to himself, “It’s time to sell this soldier some expensive gimmicky gun” and so the clerk pulled out the Five-Seven and explained how it had low recoil and armor piercing ammo (any commercial ammo above 2000fps is likely armor piercing, including the standard commercial loads for the 5.7x28mm). Hasan said he would go home to do more research. As fate would have it, he bought the pistol, along with an expensive laser sight and plenty of ammunition to practice with on live human silhouette targets.

By the time his attack was over, Hasan had killed 13 people and wounded 32, but that does not tell us much information about how this round is effective or ineffective.

Consider a few things. If you are in a shoot out, you have a limited amount of time to deliver fire onto the enemy. During this time, the speed of your follow up shots, the accuracy of those shots, the time between reloads, and the effectiveness of each individual shot all come into play.

A good contrast would be this: Two people are in a shoot out at 25 yards. One has a single shot elephant gun. The other has a Five Seven pistol. I would much rather be shot with the pistol than the elephant gun; however, if the guy with the elephant gun missed, he would almost certainly be riddled with bullets by the time he even managed to get a second shot off due to the punishing recoil, muzzle climb, and time spent cycling the bolt.

So if you had to rate a weapon according to the criteria below, how would it score?

Time / Splits between shots in seconds?

Shot grouping while rapid firing at 10 yards (or any distance at which you expect to use it)?

How long can you fire before having to reload, in seconds?

Comparing the 1911 to the Five Seven

Let’s compare the old tried and true 1911 in 45ACP to the Five Seven in 5.7mm. Your shot splits might come close, but I would bet my life that the shot grouping would be tighter on the hot .22 than the big push of the .45 The Five Seven can also fire three times for every one time the 1911 will fire. Furthermore, if you go to “brassfetcher ballistics” on youtube and compare the wound channels created by either of those rounds, the 5.7mm penetrates just as much and tumbles end over end, creating a wound channel just as effective at putting a lethal hole in something as the .45. This is not to mention that the tumbling effect has the added bonus of having the tendency to wind and snake through the target, increasing the possibility it might strike that vital organ or artery and cause a fatal wound. It also is very loud, and there is a psychological advantage to having your weapon sound like “KABOOOOM!” while their pistols sounding like “Bang”.

So sure, a hot .22 pistol doesn’t sound that impressive; however, considering the volume of accurate fire that will come out of it, the combination of those factors make it extremely formidable. If you have a standard pistol with say 15 rounds, you will run out of ammunition and be experiencing sheer terror as your opponent with the 5.7 is moving in on you firing away and still having 15 rounds to finish you off. The medical personnel at the Fort Hood shooting commented that the amount of bullet wounds in the people arriving at the hospital was staggering. It’s not often that one round will decisively put someone down for good but a stream of controlled fire putting multiple hits rapidly on target, thereby increasing the odds of inflicting a fatal wound, is quite deadly.

Also consider, if you have to face multiple attackers in rapid succession, you are at a hugely vulnerable state anytime you have to reload. Again, the 5.7 wins with capacity. You can engage and defeat, one, then two, then three, then who knows how many before even having to change one magazine out, and because the ammunition is so light, you can easily carry even more magazines than other standard handgun rounds.

On accuracy while rapid firing, in a shoot out at the most common distances, being able to shoot the X out of a target is irrelevant. Being able to dump rounds rapidly into center mass until the target stops moving is what’s important, and again this round allows you to do that and even do so one handed. Try rapid firing one handed with a .45 and seeing how accurate you are. Being shot in the arm happens all the time. How many people ask themselves, “How well could I handle this gun one handed while bleeding and outnumbered?”

Imagine being outnumbered three to one and you are wounded, and you’re just about to hit slide lock on that 10-round Wilson combat 45ACP magazine. You’re dead. But if you have a 5.7 with a 30-round magazine, your 30 shots of light recoiling high velocity ammo might be enough to save you, since you can control them while still firing rapidly and not have to worry about reloading until 30 rounds have been expended. That’s a lot of rounds to work with.

It is not all about the one perfect shot. Combat shooting at modern engagement distances is about delivering plenty of rounds on target, rapidly. It’s suppressing, flanking, and killing the enemy. The 5.7mm is pretty near perfect for this.

Next is the PS90. This PDW shares all the same benefits of its handgun counterpart. You can easily carry twice the ammo over 5.56mm, reload half as often, and maintain a suppressive volume of fire to either move in and finish them or retreat.

The Cons

You better be stocked up on ammo ahead of time. However, this can be done. It’s not too big of a con, in my opinion. If you survive through your 5000 rounds of 5.7mm and actually used all that ammo to take out a dozen bad guys or what not, you likely will have recovered their weapons and ammo as battle field pick ups.

Dealing with the lack of range and penetrating power, it’s the same problem as the 5.56mm when compared to 7.62mm but even worse. This is a micro 5.56mm essentially, so punching through a tree to hit a bad guy is not going to happen. You must be aware of your unique environmental considerations. There are places in the world where this cartridge would be a dismal failure, like a dense jungle, and where 30 caliber penetrating power is needed. But other places it may excel. Even so, with AP rounds that are restricted to LE/military, it is still impressive at close ranges.

If you’re in a team of people who are preppers, you might be the odd man out with your novel magazines, manual of arms, and ammunition. If everyone is running AR15s, maybe you should just run them as well, for easy logistics, for magazine sharing in a fire fight, and so everyone knows how to run any gun in the team.

As I said in the start, I see this as a specialized round with specialized weapons. It is up to you to figure out if it is right for you. Maybe there are people small in stature or strength who would be best served by using such a light weight, light recoiling weapon. Maybe you see a utility in having a concealable weapon with plenty of firepower. Maybe you could talk to your group about the use of the PS90 as an excellent suppression system. A few guys with PS90s and stacks of 50 round magazines nearby could lay down a blanket of accurate deadly fire out to a few hundred yards.

This is merely an article for your information. I know the people who read this blog are thoughtful and intelligent and will take what information they need and store away the rest.


Take care.