SDS Imports Duo-Sys Force DSF12 12 Gauge

The 12-gauge pump shotgun is a mainstay for home defense and as a truck gun. Pump actions offer ease of use, easier maintenance, and versatility because they can be loaded with shells that range from non-lethal types and bird shot to 00 buck and slugs that can still be cycled through the gun. Also, pump shotguns are typically less expensive than semi-autos, which require more maintenance and can be finicky with light target loads. We gathered three 12-gauge pump shotguns and put them in the hands of our testers to evaluate the guns with an eye toward gauging affordability and assessing performance, two traits that are not usually found together. The pump guns matched up in this review include the Mossberg Maverick 88 Security, $264; Savage 320 Tactical FDE, $270; and the SDS Imports Duo-Sys Force, $469.

First, let’s look at the similarities. All are designed for defense work, are chambered for 3-inch 12-gauge shells, and are equipped with polymer stocks. From there, the Mossberg and Savage are on the pump-gun side of the fence, and the SDS plays on both sides of the fence, operating as a semi-auto and pump. We found features we desire in a defense gun, such as ease of loading, smooth cycling, easy recoil management, sights that are fast to acquire, and adequate round capacity. If there are aftermarket parts available, that’s all to the better so we could customize the shotgun to fit our needs.

We found we could have both affordability and performance. In our opinion, the Savage and Mossberg offer features desirable in a defense shotgun at a cost that pleases our wallets. The SDS, with its hybrid action, is more expensive, but it allows the shotgun to run on any ammo you feed it, just make sure it is in the correct mode. Yes, as you might have suspected, the SDS M3 clone didn’t cycle light target loads, which we will get into.

How We Tested

We used IDPA-style targets set at 15 yards and fired all rounds off hand to gather shot patterns and slug-group data. With the Savage and Mossberg, we couldn’t control the patterns as much as we wanted because both of these guns use a fixed Cylinder choke. The SDS uses choke tubes, which enable the user to be surgical with the Full choke tube. Ammo consisted of a light target load, Federal Ultra Clay & Field No. 8 shot with a factory muzzle velocity of 1255 fps. Defense loads were Aguila High Velocity rounds with 0 buckshot (1275 fps factory muzzle velocity), Panzer Defense 00 Buck (1350 fps factory muzzle velocity), and Hornady Critical Defense 00 Buck (1600 fps factory muzzle velocity). We also fired Federal Hydra-Shok 1-ounce rifled slugs. Note that factory muzzle-velocity data is included in the Range Data table. You will see why we included the velocities, especially for the SDS shotgun. Hornady and Federal loads provided more felt recoil than the 00 buck loads. We could have fired the light Federal loads all day long, and in fact, we did. Using the push-pull method of recoil control, we pushed the fore end with our support hand and simultaneously pulled back on the pistol grip with the firing hand just before loosing a round. This method minimizes the punishing recoil 12-gauge pumps can dole out. We shot one target to obtain pattern and group data, then fired for speed on another target. 

Stock styles included fixed pistol-grip tactical buttstocks on the SDS and Savage. The Mossberg was equipped with a traditional-style stock. Our team slightly favors this stock over the pistol grip, for reasons we’ll get into. The top line is the Savage and Mossberg chugged through the range test with no hiccups, but the SDS had initial FTE jams when it was eating light loads in semi-auto mode. We would use any of these shotguns in a heartbeat to defend ourselves, but we had our preferences. Here are the details on these shotguns.

SDS Imports Duo-Sys Force DSF12 12 Gauge

$469

Gun Tests grade: B+

Only ran on high-velocity high-brass ammo in semi-auto mode; low-velocity loads did not cycle in semi-auto. The LOP was too long for an average person to comfortably cycle in pump mode. Patterns were surgical with the Full-choke tube, and slug groups were tight. 

The Duo-Sys Force is another knock off, but this time of the Benelli M3. This is a unique shotgun that offers either a pump action or semi-automatic action with the twist of a switch located at the muzzle end of the fore end. Converting the SDS to pump-action from semi-automatic requires turning the lock ring ahead of the fore end counterclockwise and pulling the fore end to the rear. The lock ring is turned counter-clockwise again for semi-automatic mode, allowing the fore end to disengage from the bolt and be locked fully forward. This minimal movement unlocks the fore end and engages the action rods of the pump system, instantly converting the Duo-Sys into a pump-action. In semi-auto mode, the action bars are disengaged and the fore end is locked in place, allowing the inertia recoil system to function as a semi-automatic. Unlike many inertial guns, the Duo’s recoil-return spring is located in front of the receiver around the magazine tube, instead of a spring tube in the buttstock.

The way the pump action works is also different from typical pump shotguns. There in no need for an action-release button due to the Duo’s rotating bolt head that locks into the barrel extension when the fore end is pushed fully forward. To open the action, simply pump back. Also different is, after the last round from the magazine is ejected, the action locks open in pump mode and semi-auto mode. 

The Duo action works differently from the typical Benelli inertia-action gun. The Duo’s action releases a shell from the magazine each time the bolt is opened, so the user cannot swap loads in the chamber like most other Benelli guns. 

In semi-auto mode, the SDS uses an inertia action, which basically uses the force of the shot to compress a spring in the bolt, then the action rebounds forward for the next shot. An inertia action has more felt recoil than a semi-auto gas action, but the inertia action stays cleaner and has fewer parts and is usually lighter than a gas gun. The downside with some inertia actions is that they can be finicky with light target loads, which can cause failure-to-eject (FTE) jams. In fact, the SDS would not cycle light loads even after a substantial break in. According the manual this is not unexpected, and really not an issue with the SDS because the action can quickly and easily be converted to pump-action to cycle light target loads.

The Duo came equipped with a tactical pistol-grip stock with rubber recoil pad. The LOP was long, in our opinion, especially when shooting in pump-action mode. The small fore end required short-stature users to reach for the fore end, which can make shooting the Duo uncomfortable. The pistol grip is rubber with finger grooves and provides an excellent gripping surface, even when running the 12 gauge fast. The fore end is ribbed.

The Duo comes equipped with a 19.7-inch barrel that accepts choke tubes. We liked the choke tubes because they allow the user to tighten or loosen patterns. Standard features include a Picatinny rail mounted on top of the receiver. The adjustable ghost-ring rear sight attaches to the rail so it sits about quarter of an inch higher than if it were mounted directly to the receiver. Some shooters had to readjust their cheek weld on the stock to use the sights. The front sight is a post with a red fiber optic protected by wings, another rugged setup.

The manual crossbolt safety is located behind the trigger and is set up for a right-handed shooter. The charging handle is oversized, which makes manipulating the bolt easier and faster. The bolt-release button is located under the ejection port. The cartridge-release button is located on the lifter. Press this button after loading the magazine tube to release a shell onto to the lifter. Loading shells into the magazine smoothed out with use.

The manual states 100 rounds minimum are needed to break in the SDS. Going hot initially with the Hornady Critical Defense rounds with a 1600-fps muzzle velocity — the fastest ammo tested — did not cycle the SDS in semi-auto. Neither the Panzer nor the Aguila cycled either. The light Federal field load did not cycle. The SDS choked on the Federal slug, too, in semi-auto mode. We still fired it knowing there was a break-in period, and finally, after 100 or so rounds, the SDS would eject, but only the Hornady rounds. Perhaps putting more shells through the gun would allow the shells with less velocity to cycle. 

In pump mode, the SDS initially did not go into battery, because, it seemed, the bolt was not rotating and locking in place. Vigorously cycling the pump solved the problem. The SDS then chewed through whatever we loaded into it. The pump cycled smoothly, but the short fore end required average-stature shooters to reach for the fore end, and the longish 14.2-inch LOP made shooting the SDS uncomfortable when we had to reach for the fore end. Recoil was tolerable.

The Hornady buckshot patterned at 4 inches, while the Panzer and Aguila patterned at 9 and 9.5 inches, respectively. The choke tubes make the SDS more versatile, in our opinion. The Federal bird shot was a tight 10 inches. With the Federal slugs, we averaged 3 inches. The sights are large and obscured the target, but that didn’t stop us from doing good work with the Duo.

Our Team Said: The Duo gives the user all the advantages of a semi-auto with the reliability of a pump, which we needed with this sample. We would run more high-velocity ammo through it in semi-auto mode to ensure the Duo is broken in and reliable as a self-loader before using it as a defense gun in that mode. In pump mode, the Duo ran flawlessly after an initial break in. The Duo cost $200 more due to the hybrid action. We could run all the ammo tested through the Duo, but only in pump mode, and that’s the function we graded it on.

To collect pattern data with shotshells and groups with slugs, we fired off hand at a distance of 15 yards.

Written and photographed by Robert Sadowski, using evaluations from Gun Tests Team members. GT