The MARCK-15 Hydra Modular Weapons System by MG Industries is a modular AR-style gun platform which allows shooters to quickly and easily re-configure their gun to shoot different calibers. It uses standard rifle barrels, standard magazines, and many other off-the-shelf parts along with modular Hydra MWS components to make in the field changes to configuration and caliber in seconds without tools. Currently, the Hydra MWS can be configured for more than two dozen calibers including .22LR, .223/5.56, 6.5 Grendel, 6.8 SPC, 7.62×39, .458 SOCOM, and .50 Beowulf rifle cartridges and 9mm, .40 S&W, and .45 ACP pistol cartridges.

To make getting started with the Hydra even quicker and easier, MGI has created packages of common set-ups. The “Starter” Set comes in a rugged lockable rifle case with custom foam inserts to hold the entire kit, and comes with everything needed to configure a MARCK-15 rifle for 9mm, .22LR, and .223/5.56. It includes the base lower receiver, a 9mm magazine well, a QCB-D upper, a 16 inch bull barrel, and a 9mm bolt unit. To re-configure the 9mm carbine for the other calibers, shooters swap in the included bolt carrier group, barrel, and magazine well, plus a drop-in kit for .22LR rimfire if desired. The 9mm configuration uses Colt-style magazines.

The “Survival” Package includes four calibers: 9mm (using Colt style mags), .223/5.56, 7.62×39, and .300 Blackout. The kit comes in a case with custom foam insert and includes four barrels, three bolt units, and three magazine wells.

These kits deliver ready-to-go units for multi-caliber shooting right out of the box. Additionally, shooters can add Hydra components to expand their options even further. To make the Survival kit a truly all-in-one solution, for instance, it might not be a bad idea to throw in the .22LR drop in unit. Each shooter will have the opportunity to pick and choose Hydra components to optimize Hydra compatibility with the rest of his or her inventory.