Design

• These two shotguns both use a single barrel. The M2 Field and M2 Tactical variants feature a standard rifle grip, while the M4 always offers a pistol grip. Buyers can purchase a variant of the M2 Tactical with a pistol grip as well. This latter grip style enables greater versatility in firing from the hip, shoulder or when needing to maneuver the weapon in urban combat situations; the M4's shorter overall length also gives it greater maneuverability.
  
  

Operation

• The M2 and M4 differ in operation. The M2 uses Benelli's inertia operation to chamber each successive round. This design uses a spring-loaded recoil driven system; after an operator fires a round, the M2's recoil compresses a spring that ejects the empty cartridge and reloads the next round. The Benelli M4, by contrast, uses the company's Auto-Regulating Gas-Operated (A.R.G.O.) system. This gas-operated method reloads and ejects each successive round via the action of three gas pistons. This configuration gives the M4 faster cycling, less recoil and lowers the chance of a jammed round, providing soldiers and police faster, more accurate firing during combat situations.
  
  

Dimensions

• An M4 comes with only one 18.5-inch barrel length. This barrel gives the M4 an overall length of 40 inches. These weapons weigh 7.8 pounds. The M2 Tactical features an 18.5-inch barrel with an overall length of 39.75 inches and a weight of 6.7 pounds. Buyers can purchase the M2 Field in multiple barrel lengths of 21, 24, 26 and 28 inches, yielding an overall length of 42.5, 45.5, 47.5 or 49.5 inches and a weight of 6.9, 7.0, 7.1 and 7.2 pounds, respectively for the 20-gauge models. A 12-gauge M2 Field comes in two barrel lengths, 26 and 28 inches, with overall lengths of 47.5 and 49.5 inches and weights of 7.1 and 7.2 pounds, respectively.
  
  

Ballistics

• Both the M2 Tactical and M4 fire 12-gauge rounds. Benelli also manufactures the M2 Field with a 20-gauge bore. As Benelli intends for operators to use the M2 Field for hunting, offering this weapon in multiple bores enables hunters to kill multiple types of game with the M2. The M4 holds five rounds total, one in the chamber and four in the magazine. An M2 Tactical holds six rounds total, with one in the chamber and five in the magazine while an M2 Field only holds four rounds total, with one in the chamber and three in the magazine.
  
  

Sights

• Benelli drills the receivers on both the M2 and M4 to enable operators to install a variety of optics and/or sights. The M2 Tactical features a standard pair of front and rear iron sights; buyers can choose between a ghost-ring or rifle rear sights to accompany the front post sight. The M2 Field has a red bar front sight. The M4 includes a rear ghost-ring and front post iron sights painted with tritium to enable targeting in low-light conditions. Operators of the M4 can adjust the rear ghost sight for both wind and elevation. The M4 also features a standard Picatinny rail system for mounting optics and other attachments