Beretta CX4 Storm carbine is the first in the new line of Beretta's "xX4 Storm" firearms, which now also include PX4 pistol and RX4 semi-automatic rifle in 5,56mm/.223 caliber. CX4 carbine first appeared in 200x, with intent to provide civilian shooters with compact and handy sporting and defensive weapon in all major pistol calibers. In developing this weapon, Beretta's designers paid a great attention to both aesthetical and practical aspects of weapon. CX4 Storm carbine has elegant appearance and is comfortable to use; it can be easily adapted for right- or left-hand use (requires a disassembly and probably a visit to gunsmith - at least it is recommended so by manufacturer). Beretta also provides a number of useful accessories for this weapon, such as user-installable Picatinny rails, stock extension pads, etc. Like any other pistol-caliber carbine, it can be fired accurately to ranges of up to 100-150 meters, especially if fitted with low-magnification telescope or red-dot sight. All in all, it is a versatile short-range carbine, with minimal recoil and excellent handling characeristics.

Beretta CX4 Storm carbine is blowback-operated, semi-automatic weapon which fires from closed bolt. Bolt is of wrap-around type, with most of its weight being located in front of he beech face, around the barrel. Cocking handle can be installed on either side of the gun and extractor and ejector can be set up for left- or right-side ejection (gun has ejection ports on either side). Receiver halves (upper / front and lower / rear) are made from impact-resistant polymer and assembled using one cross-pin, located in front of the trigger guard. Trigger is of single action type, with internal hammer and a number of integral automatic safeties which prevent firing if gun is bumped or otherwise handled roughly. Manual safety is of cross-bolt, push button type, located above the trigger and can be set up for left- or right-side operation by any competent gunsmith. Gun is provided with bolt hold-open device which can be engaged or disengaged manually through the lever above the grip. Magazines are inserted into pistol grip, and magazine release button also can be set up on either side of the weapon. Beretta CX4 Storm carbine uses Beretta pistol magazines, either of Beretta 92 / 96 type (in 9mm and .40SW respectively) or Beretta 8000 / 8040 / 8045 type (in 9mm, .40SW and .45ACP respectively). Type of magazine used is determined by special grip inserts. Standard sights include front sight, adjustable for elevation and windage (for zeroing) and flip-up rear sight of diopter type. If user desires to install a telescope or red-dot sight, an optional Picatinny rail shall be attached to the top of receiver. Up to three optional short accessory rails also can be installed at the front of receiver, at 3, 6 and 9-o'clock positions. CX4 Storm carbine also is provided with sling swivel studs.