The receiver is made of an impact modified glass reinforced Zytel. The front end houses a hinge block holding the barrel and the rear site. This block is securely locked in place by a swiveling trigger guard. The receiver rigidly attaches to the stock by multiple lugs. The bottom of the receiver forms the pistol grip, also accepting different magazines according to the version specified. The receiver also houses the firing mechanism. The 4130 ordinance steel barrel has a spring loaded collar to ensure an accurate lock between the receiver and the polymer forend and the fully adjustable front sight. The forend also has integrated the ability to house batteries and/or other small devices. The tubular steel stock contains the bolt and is ended by the polymer butt stock. The heavy two-piece steel bolt holds the firing pin, the extractor and has the operating handle on the bottom. A captive guide recoil spring with buffer actuates the bolt. The firing mechanism is of conventional single action type. It has a positive disconnector, a push bolt safety that blocks the sear and disengages the trigger bar. The hardened steel ejector is internal. This design, with its long bolt travel, allows for very large functioning marginals.
The basic SUB-2000 design is implemented in a rather unusual folding design that folds for storage into half its total extended length. Folding is accomplished by pulling downward on the trigger guard and swinging the barrel assembly back over the top of the rifle. A latch in the buttstock secures to the front site housing, and the gun can be locked with a key in the folded position for added safety. The gun cannot be fired when folded. Even when folded, it is still 16 inches long, and not easily concealed as some would claim.
The SUB-2000 has an effective range of over 100 m. At distances closer than 50 m, the 9 mm bullet approaches the muzzle velocity of a .357 Magnum. At 200 m, velocity approximates .380 ACP muzzle velocities. The SUB-2000 weighs 4 pounds (1.8 kg) unloaded.