  the sub-2000 is a pistol-caliber carbine manufactured by kel-tec cnc industries of cocoa, florida, united states. the rifle is a blowback operated, semi-automatic firearm with its operating spring located in the tubular stock. it feeds from a grip-located magazine well using magazines designed for various pistols, and is an inexpensive carbine. the distinguishing characteristic of this rifle is that it folds in half for storage and transportation, and its extreme slim shape compared to other rifles. the weapon accepts magazines from semi-automatic handguns. the main advantages of a carbine in a pistol caliber over a handgun include the increased sight radius which aids with accurate shooting; the long barrel more efficiently captures burning powder which increases projectile velocity; and more points of contact between the shooter and weapon which increases stability. ==design== it is available in two versions chambered for 9 mm or .40 s&w caliber cartridges. it was designed by george kellgren, a swedish-american designer who also designed many earlier husqvarna (in sweden), intratec, and grendel brand firearms. the receiver is made of an impact modified glass reinforced zytel. the front end houses a hinge block holding the barrel and the rear sight. 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 ordnance steel barrel has a spring-loaded collar to ensure an accurate lock between the receiver and the polymer fore end and the fully adjustable front sight. the fore 
Semi-automatic_rifles