The XM-26 LSS (Lightweight Shotgun System), otherwise known as the M26 MASS (Modular Accessory Shotgun System) is a bolt-action shotgun manufactured by C-more Competition. The shotgun is usually seen in a under-barrel configuration on assault rifles and carbines or a stand-alone configuration.
Tom Clancy's Rainbow Six: Vegas
The XM-26 LSS is a weapon featured in Tom Clancy's Rainbow Six: Vegas. It's only seen in a stand-alone configuration, and can not be mounted on to assault rifles at all. The XM-26 LSS is the only semi-auto shotgun in the game.
Tom Clancy's Rainbow Six: Vegas 2
The XM-26 LSS is a weapon featured in Tom Clancy's Rainbow Six: Vegas 2. Since Vegas 1 and 2 share the same engine and models, the weapon appears in the same configuration as its Vegas 1 counterpart. Once again, it is only seen in a standalone configuration, and is the only semi-auto shotgun in game.
Tom Clancy's Rainbow Six: Vegas 1 & 2
- The weapon in-game is incorrectly shown as a select-fire semi-auto/full-auto shotgun. In real life, the weapon is only bolt-action.
Tom Clancy's Rainbow Six Siege
- While not present as a weapon in-game, Buck's "Skeleton Key" underbarrel shotgun attachment is heavily based on XM-26 LSS.