SHOT 2025: Marck-15 Hydra 10mm H21 Is A Hard-Hitting PCC
Maine-based Hydra Weaponry has beefed up their pistol-caliber carbine game with a new 10mm option. At SHOT Show, they’re displaying their new Marck-15 Hydra 10mm H21, a new configuration of their Hydra semi-auto design.
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Hydra’s claim to fame has long been their switch-your-caliber AR-pattern designs, allowing them to run a wide range of calibers from a rifle with only a few basic parts changed out. In this case, the Marck-15 Hydra 10mm H21 is configured to use Glock-pattern magazines (chambered in 10mm, of course). The rifle comes with the Hydra Modular lower receiver, the 10mm H21 magazine well, the Hydra Quick Change Barrel Upper Receiver (QCB-D), a 16-inch Hydra 10mm Blowback Barrel, a 10mm Blowback Bolt, and a stock and pistol grip from B5 Systems.
Rails along the top and sides of the barrel shroud make it easy to attach optics and other accessories, and a rail underneath the barrel is ideal for a light or a foregrip. This rifle ships with a single Glock-pattern mag as well. Buyers can opt for M-Lok, Picatinny or Keymod inserts on the rifle.
But all this is just a starting point. Hydra says: “With this base rifle, you can purchase and utilize the rest of an ever-growing system including our various magazine wells and caliber conversions. To convert this system to another caliber, the most you will need to change is the barrel, bolt and bolt carrier, and magazine well to the desired caliber.” So this PCC is like their other Hydra-system rifles, and easily converted to 9mm or other chamberings.
This clever design work is probably why the rifle weighs 10 pounds, which is more than many of us would like for a PCC, but versatility comes at a cost. And not just a weight cost; MSRP for this rifle is $1,400-$1,538. See more details here.
Professional hoser with fudd-ish leanings.
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I had thier Glock mag/bolt/barrel 9mm kit for my 556 hydra.
Fired before lock up blew mags out of the rifle. Called them and they said sent the kit back and they would test it and fix/replace it. Sent the kit back, over half a year later they said they were still working on what was causing it, severalonth later still working on new design, and again next time I called, they then said we will just give you an ak magwell bolt and barrel, to which I said send me a refund. It was years before g9 kit was back on website. Not sure I want to get early 10mm from them. If the 9 had worked I'd be get 45acp Glock mag kit, but caliber change kits cost more than a full single caliber gun from other manufactures. Just a magwell $275, caliber kits are $650.
What I would buy but they don't sell is just their ar308 upper/handguard.
More options the better I guess.