Putting a pistol caliber cartridge in a rifle is easy…but a rifle round in a pistol? Now that takes a bit more effort…
In a world of 9mm AR-15s and 10mm carbines, ammo is no longer confined to it’s standard “handgun” or “rifle” designation.
While rifles chambered in classic handgun rounds seem to be all the craze right now, we seem to forget that the opposite exists…kind of. Although not exactly a rifle round, the FN 5.7x28mm cartridge is also not quite a pistol round either.
Clearly, the Five-seveN is truly a unicorn of the gun world. It is a lightweight polymer pistol that shoots FN’s own 5.7x28mm round.
When NATO requested an alternative to the 9x19mm round, FN Herstal was the first to respond, presenting the 5.7x28mm cartridge. The 5.7 round was originally developed for the P90 until the Five-SeveN pistol went into production in 1998.
In the early 2000s, NATO conducted a series of tests with the goal of standardizing a personal defense weapon round and replacing the iconic 9mm.
The 5.7x28mm surely impressed—it was highly effective, performed at extreme temperatures, and could even be manufactured on the same production lines as the loved 5.56x45mm NATO round.
Effective range when shot from a Five-SeveN: 55 yards (maximum range of 1651 yards!)
Total Weight: 6.0 grams=93 grains (half the weight of a 9mm)
Projectile Mass: 28-40 gains
Velocity: 2,350 ft/s (FN 28gn, JHP)
The Five-SeveN is a full-sized pistol and a compact-sized weight. It has a nearly completely polymer frame, with some small steel internal components.
While the grip is considerably thinner than most full-sized pistols and a bit long, which could be a bit uncomfortable for some hand sizes, it features ambidextrous controls that are conveniently placed for thumb or trigger finger manipulation.
Although the grip can feel a bit odd at first because it is so untraditional, it grew on me as I manipulated the gun and actually shot it.
Adjustable rear sights for both windage and elevation, which is important because of the round’s uncommon ballistics.
Since the 5.7×28 cartridge is so small it is easy to fit a lot of ammo into a single magazine, especially when using a double stack-double feed design.
The design of the magazines is equally brilliant and lightweight. They hold 20 rounds and load in a similar fashion to standard AR magazines–you simply push the round straight down instead of maneuvering it in and under like in most pistol magazines.
The Five-SeveN is also easy to disassemble with a simple takedown lever.
Shooting the Five-SeveN is an absolute BLAST.
Imagine the almost non-existent recoil of a .22 LR juxtaposed with the noise of an AR. The first few shots fascinated me yet confused me.
I had never shot anything like it and could easily tell it is one-of-a-kind.
The lightweight frame makes for a comfortable range session while magazines are a breeze to load.
Sadly the rigger is not the greatest but features a pretty crisp break and moderate pull weight, my groups were pretty consistent with how I would normally shoot a handgun; maybe slightly better at longer ranges – likely due to the high velocity of the 5.7 ammo.
I could see this gun being liked across the spectrum, from novice shooters to seasoned vets.
Looks and Accessories
The Five-SeveN has a sleek and almost futuristic look to it. It comes in either an all-black finish or a tan frame and black slide (my personal favorite).
The rail can be outfitted with a flashlight and aftermarket night sights are available for purchase as well.
Threaded barrels do exist for this gun and I can only imagine what a great time it would be shoot suppressed.
The 5.7x28mm cartridge was designed to meet a goal and in that role it is unequaled – but the Cold War is over and the need for armor penetration in an EDC is limited at best.
There is quite a bit of debate surrounding the topic of whether the Five-SeveN can be used as an effective carry gun:
On the pro side, it is extremely lightweight, has a decently heavy trigger pull and safety, very high magazine capacity, and effective stopping power.
Looking at the cons we have expensive to shoot ammo that is only available in FMJ, and the high possibility of over penetration due to such a fast round.
As with most things, it is a personal choice as to whether this is a viable carry gun or just a fun range toy to make your friends jealous. However, we tend to be on the side of the fence that says there are Better Options for Full-Size EDC.
By the Numbers
Nice grip texture, super lightweight, but an oddly shaped grip could be uncomfortable for some.
Better than most handguns, especially at longer ranges.
I had no issues with it jamming, ever. After doing some research I did not conclude that there were any known reliability issues and NATO testing definitely backs up the effectiveness of the round.
This category is lacking a bit because the gun is not very common and the design is unique. It might just be better to leave it as it comes from the factory and trust FN’s creative design.
I like the almost futuristic and very sleek look, but it does not necessarily look special, especially for the price.
This is the real kicker. The actual gun is expensive and the ammo also expensive. While it could make a great splurge purchase, it is not exactly a cheap plinker.
Really the only downside to this gun is the price, not only out the door of your FFL but also in trying to keep it fed. There is also the fact that although 5.7x28mm was a perfect solution the problem it was designed for – there just isn’t much of a need for it currently.
But, if you have the money and the desire, it will always turn heads at the range.
If you have the chance to shoot a Five-SeveN, you should. It is unlike any gun I have ever shot and is truly a remarkable weapon.
The unicorn of the polymer pistol world is definitely not for everyone but has surely caught the attention of many. An amazing combination of a lightweight frame, high-speed but low recoil round, and loud bang come together to make the FN Five-SeveN noteworthy and intriguing.
Do you have a Five-SeveN? Plan on getting one? Let us know in the comments! Check out more of our favorite guns & gear in Editor’s Picks.
This gives me a longer handguard (with M-LOK), ability to add rails, Magpul rear flip sight, and a nicer barrel finish compared to phosphate.
Since it has a pinned FSB…it’s a little front-heavy….but that’s the nature of the beast. The FSB is pinned well and the handguard is really on there. You can see my segment of Picatinny I added to the handguard’s M-LOK attachment points.
The next upper would be my favorite overall setup. 16″ mid-length with a 13.5″ M-LOK free-floating barrel and Nitride barrel.
Now you get the benefit of not having a FSB which helps the weight balance, and also having a free-floating handguard that increases accuracy by taking away contact points on the barrel.
For absolute reliability I’d still opt for the FSB model…but free-float AR’s are now the standard, you can attach a lot of stuff, and the gas block is really on there.
The last model is the 18″ .223 Wylde which is a relatively new chambering that will shoot BOTH 5.56 and .223 but offers a slight accuracy edge. Usually you’ll see the more accurate barrels in stainless which is what we have here.
This comes in an even softer shooting rifle-length gas system and 15″ M-LOK free-floating rail.
All came with mil-spec A2 bird-case flash-hiders that were installed correctly and didn’t require superhuman strength to take off and switch for some compensators.
PSA seems to have three tiers of barrels.
Premium: chrome-lined or CHF (cold hammer forged) that are made by FN
Standard: Nitride, Melonite, and stainless barrels
Basic: phosphate coated
The two 5.56 uppers I received were Nitride coated instead of regular phosphate…while the Wylde was stainless steel.
Nitride (two left black ones) is smooth while stainless is…stainless. The BCG on the right gives you a sense of what the rougher texture phosphate looks like. Nitride is supposed to be a little tougher and I like the smooth look.
I took apart the free-floating 5.56 and Wylde. Straight gas tubes…
And at least 35 in-lb of torque on the gas block with some sort of weird spill on the 5.56.
There’s not too much to say here…everything is where it’s supposed to be.
Ejection port door works
Forward assist works
Charging handle feels mil-spec and works
T-Markings present and easy to read
Evenly phosphate coated
If I had to nitpick…there’s some super small machining marks on the forward assist for two of the uppers I had. Not even sure you can see them in the pics.
The Magpul mid-length polymer handguard is what it is. A great update to the mil-spec plastic handguard that can’t attach anything.
The free-floating M-LOK handguards work too. The thin profile feels great in the hand…but could use a little more TLC in the CNC to get rid of sharper edges.
Also the 13.5″ is a little on the purple-ish side and a little off in orientation between receiver and handguard…but nothing an Allen wrench and a small turn didn’t fix.
The more “premium” Wylde upper was properly aligned and colored.
BCG + Charging Handles
As mil-spec as they come. Everything is as it should be and the gas-keys are properly staked.
The 5.56 uppers had phosphate coated BCGs (mil-spec) while the Wylde had a Nitride coated one.
If I had to nitpick again…the coating is a little bumpier than other phosphates I’ve used, but since only the rails of the BCG contact anything…there’s no real downside.
I found that the mil-spec phosphate BCGs were not MP marked (magnetic particle inspected) while the more premium .223 Wylde one was.
All the bolts were listed Carpenter 158 steel (mil-spec) but I’ve seen some PSA models where it is 9310 steel. Fine for civilian use but if you really want mil-spec…go for the Carpenter 158. The carriers were all 9620 steel (mil-spec).
Targets were placed at 100 yards and I shot at a pace of around 1 shot per 10 seconds. 10 shots each group.
Mil-spec is 3-4 MOA which means 3-4 inch groups at 100 yards. The FSB version falls within that (targets are 8″). With PMC Bronze doing the best of the plinking rounds at around 3 MOA.
Gold Match does the best but keep in mind it’s about $1 a shot. If you’re shooting that on a regular basis you’re probably looking at other rifles (Best AR-15s).
All in all…it’s as I expected. When there’s a front sight block there’s a whole lot of stuff touching the barrel which doesn’t help accuracy. Let’s see the free-floating model.
Much better! Looks like all the groups closed up. PMC Bronze and American Eagle are pretty even at what looks like 2 MOA. Gold Match is still the ultimate winner but it’s not THAT much off from PMC and AE.
When you have a free-floating handguard there’s less contact with the barrel and the accuracy shows.
Now how about the .223 Wylde we’ve forgotten?
Since this is a more premium barrel and made for accuracy…I did a break-in procedure with it as well as with PSA’s .224 Valkyrie (coming soon).
I cleaned the barrel and shot 1 round through before using copper solvent and a brush. Repeat the shoot and clean for 5x total. Then I changed it up to 5 shots before cleaning. Repeat 5x.
I then plinked ~200 rounds.
Finally, I was ready…
I used a different lower with a Triggertech trigger which I might actually like more than my Hiperfire (Best AR-15 Triggers). I started running low on Gold Medal so the last group only has 4 rounds.
It really looks like the FSB version instead of something that uses a tighter chamber and a free-floating handguard.
I’ll continue testing but right now looks like I would stick with PSA’s regular 5.56 offerings (free-floating of course).
The thing with PSA is that they are always in and out of stock of everything. And they have almost every combination under the sun…which makes it nice but also a headache to find what you want.
No fuss of building anything…out of the box ready to go.
I again like mid-length gas systems and it looks like their Nitride barrels are GTG. Their more premium selections (CHF) should be great as well if you have a little more to spend. I haven’t spent time with their regular barrels (phosphate), but other reviews vouch for them.
I personally like free-floating M-LOK handguards since they give you added accuracy and lots of space to put stuff. Unless you really want the look of a FSB…go for free-floating!
Already have a lower and want an affordable upper? There’s a bazillion options again…so here’s a search for 16″ mid-lengths to narrow it down a little:
Radical Firearms is a relative newcomer to the AR-15 world. I first heard about them when they brought some of their work to SHOT Show in 2016 or so, but they’ve been around for about five years now.
In that half-decade, they’ve expanded rapidly and carved out a niche for themselves as one of the best budget manufacturers in the business.
How did they do that?
They decided to start making as many parts as they could in-house.
This afforded them the opportunity to exercise a high degree of control over their manufacturing, while also allowing them to cut out a lot of the middleman markup that gets slapped on rifles by “manufacturers” that just assemble guns from third-party parts, rather than making everything in-house.
And make no mistake, they are a manufacturer. They make every part of the rifles they sell, other than barrels, pins/springs, and LPKS. Their site also says they don’t make BCGs but I think that info is a bit out of date as I’ve seen a number of Radical Firearms branded BCGs out there.
They are also an American manufacturer, which I know is important to a lot of folks, and best of all they prefer to hire vets and LE personnel when they can, like many in the firearms industry.
Why I Bought The Radical Firearms Upper
This all leads me to this review and why I bought a Radical Firearms upper of my very own.
Now, like I said, Radical and PS buried the hatchet over the misunderstanding and everyone moved on. But it left a terrible taste in people’s mouth. I know the smell of PR spin when it passes my nostrils, and this felt a little…off.
So I decided to see for myself, and I didn’t want to contact Radical about getting a T&E upper in to check out.
I wanted a regular standard upper off the warehouse shelf, just like the one you would get if you ordered one.
I searched around and found one at Optics Planet and snapped it up during last year’s Black Friday sale.
I did this for two reasons.
I wanted to be as unbiased as possible, and avoid getting a T&E/review upper that might get looked over a little more on the way out the door. Not that I don’t trust the folks at Radical Firearms, just don’t trust anybody when they’re offering cheap prices.
I needed another upper, and I’m at that age now where I have to buy Christmas presents for every-freaking-body in the world, so money is tight around our house all year long. Cheap is good.
So is Radical Firearms another in a long line of fly-by-night machine shops turning out AR parts with sloppy standards and poor practices?
Or are they something else? Maybe even a sorely needed quality, American manufacturer offering good rifles at great prices?
We wanted to know, and sure to find out.
The Upper Itself
The upper we got had a 15” MLOK rail, and A2 flash hider, and not much else going for it. I like the shape of the handguard, it has a sort of quasi-rounded thing going on with a flattish bottom.
Machining is totally adequate. I noticed no rough edges, file marks, burrs, or other machining imperfections.
Everything is totally in spec and I had no problems fitting the upper to a variety of lowers, including two Aero lowers, a Spikes lower, and an Anderson lower.
Testing the Radical Firearms Upper
Now, the upper I received was sans BCG and charging handle, so I added my own until I could get a Radical Firearms BCG, which we’ll talk about it a minute.
For now, threw in a spare Aero Precision BCG and a generic charging handle that came from somewhere.
Then, throw BCM Gunfighter handles on all my guns, so this one probably came off a complete upper or something.
With that, I inspected the upper, daubed a little Dykem layout/machining fluid on the screws holding the handguard in place so I could see if they were turning or working themselves out under recoil, lubed everything that needed lubing, slapped the upper on an Aero complete lower, and hit the range.
I packed a little over 250 rounds on that first outing, a mix of Federal American Eagle, range-quality handloads, and a box of Federal Gold Medal, all with 77gr bullets to take maximum advantage of the 1:7 twist barrel.
I also slapped a Bushnell TRS red dot, my personal favorite cheapo optic, on top of the upper’s full-length rail. I chose this because I figure most people who buy these aren’t going to be putting something super expensive like the absolutely amazing Aimpoint PRO on top of it.
And again, there’s nothing wrong with a budget rifle, as long as it works. If you aren’t a precision shooter, the difference between a sub-1” group and a 2.5” group isn’t a big deal, but you will pay through the nose for the former and can throw together a rifle that’ll do the latter for about $600.
I zeroed this setup in at 25 yards, and then stepped over to the 100, 200, and 400 yard stretches to see what it could really do.
Again, this is with a mix of ammo, and honestly, I didn’t expect much out of the upper. At $190, if I could hit pie plates at 100 yards, I’d have gone home happy. I set out to build a beater gun after all.
But holy Kahuna did I underestimate this upper.
I was hitting 6” steel plates at 100 yards with absolutely boring regularity, the staccato pingpingping of rapid-fire impacts setting the plate swinging on the chains.
At fifty yards, I was left with one ragged dime-sized hole.
Reaching out to 400 yards, I was able to fairly easily smack a steel pig silhouette target, though I was pushing myself more than the rifle, and I’ll take credit for any misses.
Punching paper with the Gold Medal ammo was equally surprising. I swapped in a Vortex Strike Eagle 1-6x scope and after a quick bore sight and about a third of a mag to really dial the scope in, I was getting easy 2 MOA groups at 100 and 200 yards, and a best group of 1.8 inches (measured center to center with calipers) at 100 yards.
I noticed no keyholing or other weirdness, and I shot the full 250 or so rounds without a single issue (this was with beat up PMAGS and one steel GI mag).
Now, is any of that matching accuracy? No, of course not. I have AR’s that’ll punch ¾ MOA groups all day.
But those rifles have an extra digit on their price tag. Nowhere do I see Radical Firearms claiming to make the most accurate guns in the world for $600. I see them saying they make guns that work for $600, and their upper certainly reflects that.
Since November, I’ve put about a thousand rounds through this upper, cleaned it once, lubed it three or four times, and I’ve experienced precisely two malfunctions, both from the same mag.
That mag also had problems feeding in a $2,500 rifle where it actually causes a double feed (and some swearing).
Overall, I was very impressed with the Radical Upper I received.
The rumors and the gossip and the snide remarks are all just hot air. I think Radical Firearms is a good company that makes great products, and they are definitely a manufacturer to keep your eye on.
When I was researching them beforehand, I saw a lot of comments from others about the low quality of their products, and machining issues, and “Chinesium” and on and on and on.
But I noticed that these were always comments from people who had a “friend” who owned one. Or somebody was quoting somebody that overheard somebody that…was full of it.
I haven’t seen very many complaints ( none, really) from people who own Radical Firearms products, and I can say, since I purchased this thing with my own money, that I also have no complaints about the upper I bought and tested for this review, and others are saying the same.
Will it knock the wings off a fly at a thousand yards? Not unless you get very lucky, but not every rifle needs to be that accurate.
For me, for this rifle, I wanted something I could abuse and knock around, and still count on it to hit what I was aiming at inside 400 yards or so. And this does that.
If you’re looking for a reliable beater gun, an entry-level upper for a new build project, or even something that’s competition-ready on a tight budget, I can’t think of a better value for your dollar than these uppers.
And they’re available in everything from 7.62×39 to the hot new .224 Valkyrie, so you can get one for every occasion.
I’m happy with this purchase, and anyone who complains about a $200 upper that goes bang every time and puts rounds on target is probably just looking for something to complain about.
What do you think of the Radical Firearms upper? Would you put one on your gun?