The AR-15 is the most popular firearm design in the United States. The reason behind that fact is the gun’s ability to easily and quickly transform to meet the end user’s requirements. Everything from heavy-barreled long range precision to tiny stubby 9″ lightweight designs are possible, and swapping from one to the next can be accomplished using everyday tools and a little elbow grease. MGI recognized this fact and decided to take it one step further — why need tools at all? Why not make a gun where you can change barrels, calibers, and even magazine types easily and quickly on the range without any tools? And so they did, and dubbed it the Hydra . . .
There are two nifty enhancements that allow the Hydra to change so quickly from one configuration to the next: the barrel locking system and the magazine well.
On a traditional AR-15, the barrel is held in place using a barrel nut that holds the barrel tightly in place on the upper receiver. That barrel nut is a massive pain in the ass to work with though, and changing the barrel also generally means needing to cut the gas tube and re-install a new one afterwards. With the Hydra, the barrel nut has been replaced by two lever-operated bars. Turn the levers outward and the bars rotate, revealing a cut that allows the barrel to slide out of the rifle. Turn them back parallel and the cut is replaced by solid steel, tightly trapping the barrel in the upper receiver. Once parallel, a plastic keeper slides onto the levers to keep them from rotating and make sure everything stays nice and snug.
What’s particularly nifty about this design is that it doesn’t need any proprietary barrels or parts. Any standard AR-15 barrel and gas tube will work, and the gas tube can remain attached to the barrel the whole time. So while MGI sells a 5.56 NATO barrel kit, in reality you can buy whatever barrel you want and make it work yourself.
Changing barrels is cool, but changing magazines is even cooler.
The Hydra uses a custom-designed lower receiver that is actually two pieces. The serialized part is the fire control and pistol grip assembly, and the magazine well is a non-serialized part that can be replaced. In fact, MGI sells a kit that lets your rifle take AK-47 magazines and shoot 7.62×39 ammo, and it can be shipped straight to your door. The result is somewhat impressive.
I do have one gripe about this setup, namely that the parts aren’t keyed. An end user can quickly and easily swap things around on the gun, but there’s no system in place to ensure that the proper bolt is being used with the proper barrel. A 5.56 bolt fits in the gun when the 7.62×39 barrel and magazine well are installed, and vice versa. For those who pay attention and know what they’re doing it shouldn’t be an issue, but I would have liked to see some sort of failsafe built into the system. Heck, even just marking the bolt carrier with the intended caliber would have been nice, but nope. It’s a potential safety issue, and something to remember when playing with the gun’s guts.
The design works. With the push of a couple pins and the addition of some new parts, the gun can transform into a completely different beast. In fact, here’s a video showing how easy it is to swap from an American diet to some Soviet chow.
Before we get too much further into the review, I want to talk about the gun’s accouterments. The forward quad rail is big and bulky, but that’s a necessity for the quick barrel swapping nature of the gun. What isn’t necessary is the standard M4-esque furniture on the back of the rifle. MGI decided to stay with the standard carbine stock and A2 grip, and while their choices function properly they’re not exactly the most comfortable or fashionable choice. I would have liked to see some Magpul on the gun, but that’s just me.
That’s all well and good, but the real question is how well the gun shoots on the range.
The word “disappointing” comes to mind when we talk about the gun’s accuracy. The best group I got out of the gun’s 5.56 NATO barrel was a 2 MoA group at 50 yards, and that’s after trying a couple different brands of ammunition to find one the gun likes (Liberty Ammunition 5.56 — go figure). The 7.62×39 barrel perforated a group size nearly identical to the 5.56 barrel, so no change there. I get the feeling that this lack of accuracy is due to the mounting system for the barrel, namely the two rotating pins that hold the barrel in place. A barrel nut might be a pain in the ass to work with, but it holds things together extremely well. When you’re trying to shoot small groups, the key to accuracy is to make sure the barrel and scope alignment stays identical throughout the entire process. That doesn’t seem very possible with the mechanism in this rifle.
Another possible culprit for the accuracy issues: the trigger. IT IS TERRIBLE. I complain a lot about stock triggers in AR-15 rifles, but this one might just take the cake for worst stock trigger ever in the history of the world. Unless they were going for an 8 pound six-stage trigger, that is.
One thing I can’t fault the gun for is zero shift. Anytime I change even the slightest component related to my scope or barrel, I assume that my gun is no longer zeroed. With the MARCK-15, though, that assumption isn’t necessarily true. I spent a good half hour on the range doing nothing but shooting three rounds, removing the barrel, replacing the barrel, and then shooting three more rounds and the group never moved. I had one (large) ragged hole by the time I was done, and the rifle’s average point of impact never deviated more than a 1/4 inch from the point of aim.
Even swapping between calibers, the bullets flew straight and true. Moving from a 5.56 NATO to a 7.62×39 barrel, all I needed to do was spin the elevation adjustment turret a predictable and repeatable number of clicks and I was right back in the bull’s-eye.
The MGI Hydra MARCK-15 is a legitimately new gun. It takes the AR-15 platform and makes it even easier to swap around parts, and does it in a way that the average end user can make the changes without any tools in the field. The resulting product has its high points and low points in terms of manufacturing and design, but in general I like it. I’d just like it better with a little more attention paid to the details.
MGI Hydra MARCK-15 Piston
Caliber: 5.56 NATO
MSRP: $1,599 (Website)
Special thanks to Alamo Tactical in San Antonio, Texas for being an awesome FFL.
Ratings (Out of Five Stars):
Accuracy: * *
Not particularly accurate, but removing the barrel won’t change the point of impact and swapping between barrels everything remains on the center line.
Ergonomics: * *
The stock and the grip are straight out of the 1980’s, and there’s a reason Magpul makes tons of money these days.
Ergonomics Firing: * *
The trigger is legitimately terrible. recoil is manageable even with the 7.62×39 kit though.
Reliability: * * *
No malfunctions, no complaints. However, getting the magazine to seat properly with the AK-47 magazine well is an issue.
Customization: * * * * *
I love the engineering that went into this gun. Great idea, well executed, and functional. Some gripes about the window dressing, but the ability to swap barrels on the fly is fantastic.
Overall Rating: * * *
The direct impingement version of this gun retails for $1,300, and I’d say it’s worth the price. The piston version is $300 more, and I just don’t see the value added. Then again, I generally don’t like pistons. For the rest of the gun, there are some high points and there are some low points. Use a better trigger (ALG Defense QMS anyone?), get some better furniture, and maybe work on the accuracy a bit and we definitely have a winner. But the concept is solid, and I hope to see it improve over the next few years.