The Sentry 12: A New Kind of Shotgun

This 12-gauge takes box mags and is built more like an AR than a pump gun

I’ve always loved the idea of a pump-action shotgun fed from a box magazine. There are a lot of advantages in having a box mag instead of a tube magazine, for tactical applications and for hunters.

But I never cared for the prominent shotguns are the market that fit this bill, namely the Remington 870 DM and the Mossberg 590M. These guns are simply 870s and 590s with a magwell attached where the loading port normally goes. Most of the engineering went into the magazines themselves, but the guns were not at all built around the box magazine platform. I find them a bit awkward to use and bulky—the 870 DM a little less so because of its more streamlined, and lower capacity, magazines. They’re also unnecessarily heavy, with capacities no greater than my great handling and light Kel-Tec KS7.

Blackwater Firearms Sentry 12 shotgun.
The Sentry 12 shotgun is pump action with a 3-inch chamber and controls very similar to an AR-15. Blackwater Firearms

There’s a better way, and Blackwater Firearms may have hit a sweet spot with its new Sentry 12 pump-action shotgun, now available from the Utah-based gunmaker. I say “may have” because I haven’t gotten to test one out just yet, but the specs and info have me really wanting to.

The company says the Sentry 12, in a short-barreled configuration, was designed to be “an ideal shotgun for law enforcement,” but those same attributes should make this a great shotgun for home defense as well with a smoothbore 18.5-inch barrel with a nitride coating for the civilian market. But the thing is, the 12-gauge shotgun is built a lot like another firearm that uses box magazines: the AR.

Blackwater Firearms Sentry 12 shotgun.
A full-length Picatinny top rail allows for the use of iron sights and/or optics. Blackwater Firearms

The 12-gauge firearm has ambidextrous AR-style controls, a one-piece monolithic aluminum upper receiver, a 3-inch chamber, and weighs 6.5 pounds, that’s 1.2 pounds less than the 590M. It also uses an AR trigger pack. Does this mean aftermarket AR drop-in triggers will work with the Sentry 12? It sure sounds like it.

It measures 36 inches overall and had QD sling mounts on both sides.

On top is a full-length Picatinny rail for a range of optics choices. On the back is a polymer fixed-length stock with a thick rubber buttpad.

As far as maintenance goes, the Sentry 12 is really easy to break down. One takedown pin behind the pistol grip holds the upper and lower receivers together. The gun then breaks down into three components, the upper, the lower, and then the carriage and bolt, which are attached to the slide handle. You can even use the carriage to unscrew the barrel nut, if you need to remove the barrel in the field.

Blackwater Firearms Sentry 12 shotgun.
The Sentry 12 has a fixed-length polymer buttstock and uses 5-round detachable box magazines. Blackwater Firearms

It also comes with two 5-round magazines, which is the highest capacity currently offered. The mags, like the chamber, can handle 2.75- or 3-inch shells.

The Sentry 12 seems extremely simple, and therefore hopefully reliable, and easy to use. It’s on the light side for a shotgun and I’m interested to see what felt recoil is like with an AR-style in-line design. Though they are bullpups, the KSG and KS7 from Kel-Tec both have in-line designs, and some find the recoil from them to be punishing, especially with 3-inch magnum shells.

Additional 5-round magazines for the Sentry 12 are available for $20 each. MSRP: $899

Blackwater Firearms Sentry 12 shotgun.
Blackwater Firearms Sentry 12 shotgun. Blackwater Firearms

I don’t think gunmakers will ever be able to get around the fact that a box magazine for 12-gauge shells gets real bulky or real long real fast. Maybe a 20-gauge model is the answer? Or maybe it’s time someone came up with a rimless shotshell that wasn’t initially made for break-action hunting guns 200 years ago.

Hopefully we’ll be bringing you a full review and range test of the Sentry 12 soon!

Since the barrel is so easy to change out on this gun, I imagine a rifled barrel, a barrel that accepts choke tubes, or a barrel threaded for a comp or brake to be introduced if the Sentry 12 is successful. Plus larger magazines and different buttstocks are always a possibility, since it’s a modular design.