Benelli M4 Super 90

The Benelli M4 Super 90, also known as the M1014 JSCS, is a gas operated, semi-automatic combat shotgun currently used by Takashi Komuro in place of the Ithaca M37. While it is heavier than the Ithaca, it is more efficient in combat.

Overview
The Benelli M4 Super 90 is an Italian semi-automatic shotgun manufactured by Benelli Armi S.P.A. The M4 was the first commercially successful gas-operated shotgun produced by Benelli and is an easy to use reliable shotgun.

Plot
Acquired when Kohta Hirano opened the East Police Station's evidence stockroom to look for ammunition and guns, and tells Takashi to use it.

Trivia

 * As what Kohta Hirano said, it was basically used by the US Marines and British Army, it is heavier but its easier to use in combat because of its semi-automatic, gas-operated action. It is known in both services as the M1014 JSCS (Joint Service Combat Shotgun) (USMC),and L128A1 (British Army).
 * The Benelli M4 appears to be equipped with a Trijicon RX01. If that is the case then it shouldn't have been affected by the EMP due to using tritium to absorb light to illuminate it's reticle. It is also fitted with a door breach muzzle brake, though the make and manufacturer are unknown.