M26 Modular Accessory Shotgun System

M26-MASS (Modular Accessory Shotgun System)
The M26-MASS configured under the M4 carbine.
Type	Underbarrel Shotgun
Place of origin	United States
Service history
In service	2003–2011 (limited service) 2011–present (full service)[1]
Used by	United States
Wars	Iraq War
Production history
Designer	Ira M. Kay
Designed	1997–2002
Manufacturer	C-More Competition
Produced	2003–present
No. built	9,000+
Variants	XM26
Specifications
Mass	3 lb (1.36 kg) underbarrel 5 lb (2.27 kg) with collapsible stock 3.5 lb (1.59 kg) with stock removed
Length	16.5 in (420 mm) underbarrel 26.5 in (670 mm) stock extended / 24 in (610 mm) stock collapsed 18 in (460 mm) stock removed
Barrel length	7.75 in (197 mm)
Caliber	12 gauge
Action	Manually cycled straight-pull bolt action
Feed system	3 or 5-round detachable box magazine
Sights	Underbarrel configuration: Zeroed for host rifle M16/M4 sights Stand alone configuration: Flip up non-adjustable iron sights or MIL-STD-1913 rail attached optic

The M26-MASS (Modular Accessory Shotgun System) is a shotgun configured as an underbarrel ancillary weapon attachment mounted onto the handguard of a service rifle, usually the M16/M4 family of United States military, essentially making the host weapon a combination gun. It can also be operated as a stand-alone shotgun by attachment to a pistol grip/collapsible buttstock module. Rollout commenced in 2013, replacing the Mossberg 500 shotguns in service.^[2]