TFB Review: Springfield Armory Hellion 20-inch (Part 1)

Daniel Y
by Daniel Y
TFB Review: Springfield Armory Hellion 20-inch (Part 1)

Springfield Armory’s Hellion made a big splash when it launched last year. This import-friendly HS Produkt VHS-2 is an excellent addition to the world of bullpup military rifles. In addition to the standard 16-inch guns, Springfield now offers 18- and 20-inch models. They kindly sent me a pre-release Hellion 20-inch model for review.

Springfield Armory @ TFB:

Disclosures are important in any review so that the audience knows the full story. I reviewed the Hellion in 2022 and bought it instead of sending it back. I don’t have much of a relationship with Springfield outside of that review. Springfield provided the gun, TFB covered the ammo bill.

This is a review in two parts. Part 1 is a basic overview of this new model. Part 2 will be more in-depth with the benefit of more time with the gun, and being able to shoot it on ranges where people can see it.

What is it?

The Springfield Armory Hellion is the US-import version of the HS Produkt VHS-2. I previously reviewed the 16-inch model back when it was released, and for the most part that was a positive experience. It is a reliable bullpup that works well both suppressed and unsuppressed.

My main complaints were related to the control layout. The safety is counterintuitive and there really should be an external bolt hold open lever. As it is, it requires an empty magazine or fishing around inside the magazine well to lock the gun open.

Despite those hiccups, I still think the Hellion is my favorite 5.56 bullpup. It is more accurate than the Tavor and has a decent trigger when judged against its peers. The suppressor gas setting is also quite effective and helps the gun run about like it does when unsuppressed.

So what sets this new model apart? The only real difference with the 16″ Hellion is the barrel. All of the controls, the trigger, and the manual of arms are the same. Apart from four additional inches of barrel, this new model is finned for cooling. There is also a prominent bayonet lug on the barrel. Of course, I dug out my old M7 bayonet to see if it would fit. It did not. However, my SilencerCo Omega 300 with the Griffin Armament A2 mount did attach to the flash hider as it would on a standard A2 model.

The Griffin Armament A2 adapter fits on the standard Hellion flash hider.

Velocity Testing

One of the best things about a bullpup is the shorter overall length while maintaining a long barrel. The 20-inch tube on this Hellion is a perfect example. Despite having as much barrel as a full-length M-16, it is about the length of a 16″ carbine.

These rifles both have 20-inch barrels.

The .223 Remington and 5.56 NATO ammo both depend on velocity for effectiveness. The common rule of thumb states that 55-grain 5.56 FMJ bullets will fragment at impact velocities somewhere between 2700 to 2600 FPS. This is often extrapolated to 200 yards for a 20″ gun and 150 yards for a 16″ gun. That may be an oversimplification, but more velocity is always a good thing. On top of the fragmentation benefits, added velocity reduces drop and wind deflection.

So what kind of velocity numbers can the Hellion 20-inch put up? Here are a few loads that I tested. I used a MagnetoSpeed Sporter chrono to gather the data. It would not mount correctly on the barrel thanks to its slim profile, so I added a SilencerCo Omega 300 silencer and mounted the chronograph to it. Suppressors tend to add a few FPS so these numbers may be a little higher than would be recorded without one.

Velocity Numbers:

  • Winchester Valor M193 55-grain 5.56 NATO – 3321 FPS
  • PMC X-Tac M193 55-grain 5.56 NATO – 3134 FPS 
  • PMC 55-grain FMJ .223 Remington – 2977 FPS

As we can see, those are some very good numbers.

The Leupold Mk5HD 2-1030 fits nicely on the rail.

Magazine Compatibility

Magazine compatibility is always a question when a gun uses a standard magazine but departs from a standard design. On the Hellion, the magazine well is polymer and the gun has almost nothing in common with an AR, so it was worth checking out a range of options. A Magpul PMAG Gen M3 is included with the rifle so that is a safe bet for compatibility. I tested the following magazines which all fed, locked the bolt open, and dropped free:

  • Magpul PMAG M3 20, 40
  • Duramag aluminum 20, 30
  • Duramag steel 30
  • Lancer 10, 30
  • Okay Surefeed E2 30
  • E-Lander Steel 30
  • Hera H3 30
  • Fab Defense Ultimag 30
The Lead & Steel Promethean LP-1 gives off Halo battle rifle vibes.
Duramag's olive drab magazine looks superb in the gun.


I only have about 200 rounds on the Hellion 20-inch, so this is a preliminary take rather than an in-depth analysis. Both .223 and 5.56 ammo cycle 100%. There were a few instances with .223 ammo when the bolt did not lock to the rear, but I realized that I had left the gas system on the “Suppressed” setting after removing the silencer. So the gun will still run if you forget to switch the gas setting, but it will not lock back.

I did some accuracy work but was working with a less-than-optimal setup. A few groups with a few types of ammo averaged somewhere between 2-2.5 MOA. That is not nearly the full story though, so stay tuned for a very detailed examination of this topic in Part 2.

Check Prices on Springfield Armory Hellion Rifles


At the conclusion of Part 1, we know that the Hellion 20-inch builds on a solid foundation and puts up some impressive velocities. Part 2 will cover accuracy testing, optic selection, and other interesting rabbit holes. Keep an eye out for Part 2 when it drops, and feel free to drop a comment with things you think I should test.

TFB Review: Springfield Armory Hellion 20-inch (Part 1)

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Daniel Y
Daniel Y

AKA @fromtheguncounter on Instagram. Gun nerd, reloader, attorney, and mediocre hunter. Daniel can still be found on occasion behind the counter at a local gun store. When he is not shooting, he enjoys hiking, camping, and rappelling around Utah.

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