MGI’s MARCK-15 .50 Beowulf Now Available

MGI’s .50 Beowulf Hydra has now become available for purchase. From the press release:

Old Town, Maine (October 2014) MG Industries, manufacturer of the modular MARCK-15 AR “Hydra” platform, are pleased to announce the availability of the Hydra Modular weapon system in the hard-hitting .50 Beowulf caliber. This configuration of MGI’s modular, multi-caliber weapon system, also known as the Hydra, is fully interchangeable with the rest of MGI’s Modular Weapons Systems.

It includes MGI’s Modular Lower Receiver with an AR Style magazine-well, the Quick Change Barrel (QCB-D) Upper Receiver and a 16-inch stainless steel, bull-nosed barrel with a low profile gas block and MGI’s modified bolt carrier.

With this weapon, you can purchase and utilize the rest of the ever-growing system, including our conversion kits. To convert this system, the most you will need to change is three components: the barrel, bolt and magazine well – all done without tools. For some calibers, simply change the bolt and barrel on this weapon and the shooter will be able to fire multiple calibers, including .223/5.56, 6.5 Grendel, 6.8 SPC, .450 Thumper and the .458 SOCOM. There is no more versatile weapon on the planet, and it is now available, in stock and ready to ship.

Like most configurations of the Hydra, this weapon ships to you in a standard, hard-sided, lockable pistol case.

The .50 Beowulf MARCK-15 rifle has a suggested retail price of $1499.00

For more information, visit or your local retailer. Retailers, contact MGI to find out more about carrying the most modular rifle system in the world.

MGI Hydra.50 Beowulf Rifle Specifications:

Caliber: .50 Beowulf
Overall Length: 36 inches
Overall Height: 7 inches
Overall Width: 2.5 inches
Barrel Length: 16 inches
Weight: 7.5 lbs.
Magazine Type/Cap: AR style magazines

At 7.5lbs unloaded, the .50 Beowulf Hydra must be a handful. The MGI Hydra .50 is also available as a kit for conversion of existing Hydra rifles.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • TheSmellofNapalm

    Funny how the rifles most in need of a muzzle brake never ship with one.

    • Mack

      Ive been under the understanding that big, slower moving rounds don’t gain much from a muzzle brake, maybe porting them but not a muzzle brake.

      • iksnilol

        I just use suppressors, they don’t harm your ears (unlike muzzle brakes) and they work just as well at reducing recoil.

  • WV Cyclyin

    Wouldn’t calibers this big be better off on an AR-10 platform?

    • Steve Truffer

      No, as it was made with the AR15 in mind. Part of the design goal was “.50 in a stanag magazine, with only bolt & barrel change”.

      • WV Cycling

        I went back and decided to read up on .50 Beowulf. You’re right, it’s especially made to cater to the preexisting standards of most of the parts in an AR system.

        As you can see from my gimped username and terrible typing, I was on my phone, goofing off at work.

        Do you believe anyone has developed a cartridge that just isn’t friendly to a typical AR platform, with accommodated bolt/mag/barrel?

        DPMS, and a few others have done some 7.62/.308 AR-15’s, and with my newbish rookie knowledge, I always thought that cartridges that big should be on a lower/upper that were specifically designed for that kind of firepower.

        Thanks again guys for not blasting me to oblivion. I really do learn a lot here!

        • Steve Truffer

          7.62×39, The deign of the round just isn’t friendly to the 15’s magwell, and magazines can be spotty, at the same time offering reduced capacity. Add to this the increased bot thrust, and its just not meant for the AR. Though, to be fair, that’s why .300 blackout was designed- 7.62×39 ballistics in a stanag-friendly format.

          • Though why anyone would want 7.62×39 ballistics is beyond me…

          • Steve Truffer

            Lighter .30-30 (quintessential deer round) loads in an autoloader?

          • Spidouz

            Not necessarily 7.62×39 ballistics… sometime just 7.62×39 ammo, for many reasons, from the “behind the enemy lines situation” to the “cheap surplus ammo situation” or even a “I bought tons of ammo on that caliber but King Obama ban the AK I wanted to buy for those ammo situation” 🙂

            However, I guess most people that like 7.62×39 “ballistics” are just liking the fact to have an heavier rounds than .223 to hit, on a smaller size and weight than .308

            Just my 2cents guess

    • Anonymoose

      That’s what the .500 Phantom was for.

  • claymore

    So where is the dude mars to tell them they are using the wrong gas system length?

  • john huscio

    Looks nice, but I’m saving up for a galil ace….

  • Winter

    Anything that shoots the .50 Beowulf is awesome in my book. I LOVE my ‘Wulf….