Product Review: MGI Military MARCK 15 Hydra

The MARCK 15, also known as the Hydra, comes with a four-position rear stock, tactical flat-top rail, and a four-sided Picatinny-rail hand guard

There are many manufacturers offering AR-15 rifles and variants to Law Enforcement. A person can become overwhelmed when researching which AR-15 to choose or build. Many people are building a rifle by purchasing a lower receiver from different manufacturers — I am issued a Bushmaster AR-15 as a patrol rifle and routinely qualify with it. So when I recently received an MGI Military MARCK 15 Base System for testing and evaluation I thought it would be the regular AR-15. I would be thoroughly surprised and once I hefted the rifle I was impressed at its weight and balance.

The MARCK 15, also known as the Hydra, is built in the AR-15 configuration and comes with a four-position rear stock, tactical flat-top rail, and a four-sided Picatinny-rail hand guard. It is a rifle that can be changed from one to several calibers in less than two minutes.

A Modular System
The Hydra is ready to fire out of the box and is touted by MGI Military as “the first truly modular weapon system on the planet. It is designed with the end user in mind.”

This weapon system is unique because of the Quick Change Barrel (QCB). The QCB allows you to change the barrel by moving the securing block under the hand guard forward. Once the securing block is out of the way, the user moves two pins to the sides of the hand guard and the barrel slides easily slides out. To replace the barrel you just repeat the steps in reverse.

A unique feature of this weapon system is once the delta ring assembly, the barrel nut and the front hand guard retainer are removed from any standard AR-15 barrel, you can install that very barrel on the MARCK 15.

To continue the caliber change you must change the bolt carrier to the specific caliber on the upper receiver and change the magazine well on the lower receiver to the specific caliber.

To change the mag well on the lower receiver, you must clear and ensure the weapon is empty and safe. Press the detent button on the trigger guard to open the trigger guard, press the magazine release and lift it up to clear the mag well from the lower receiver. To reassemble just repeat the actions in reverse with the selected magazine caliber.

The caliber change can be completed without the use of any tools.

A Wide Variety
The MARCK 15 comes as a 5.56 (.223) but is offered in several calibers including 9mm, .45 caliber, 450 Thumper and .50 Cal Beowulf to name a few.

As advertised it is ready to fire out of the box. I fired the rifle at our range and found the balance helped reduce the recoil and found it to be lower than my Bushmaster patrol rifle.

Because the rifle comes from the factory without a rear sight, I purchased a Magpul Back Up rear sight and added a Tapco vertical foregrip.

I believe this weapon system is ideal for those law enforcement officers who would like to have a choice of calibers and be to adapt to a particular situation. My thoughts are to have the standard .223 variant for reaching out to the target and a 9mm or .45 caliber barrel, bolt carrier, and mag well for close quarters.

The MARCK 15 Hydra Weapon System retails for $1,250.00, comes with one polymer 30-round magazine and a hard plastic rifle case.

MGI Military is based out of Old Town, Maine. To view a video of the MARCK 15 Hydra in action on their web site, go to

Stay safe.

About the author

John Rivera is a Patrol Officer with the Bremerton Police Department. John’s career BPD started as a Volunteer Reserve Officer and while he volunteered his time as a reserve officer he work as Police Officer at Naval Base Kitsap. He was hired full time in 2006 and attended the Washington State Police Academy. While at the academy, John was selected as the class “Techy” to help with the technologically deficient class instructors. Before John’s law enforcement career, he gained his computer experience through earning a degree in Computer Programming and then working in the computer industry as a Network Administrator and Systems Engineer for several companies.

Contact John Rivera

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