Markings on the loader claim it to be a 'Raider BB Rifle'. It is nearly identical statistics-wise to the standard BB Gun, save for better durability, a slightly higher crit chance (1.5 instead of 1), and an extremely high critical damage boost, bumping it from a base damage of 4 to a whopping 70 on a critical hit (compared to the standard variant's critical damage of 6.2) furthermore, with the correct perks, this can be raised all the way to 157. It comes with the long barrel modification built-in and has a lighter-colored stock with a drawing of an angry beaver holding a rifle on it. The fictional 'Frag Grenades' returning from Fallout 3 seem to be a hybrid of the Mk 2 hand grenade and the Type 91 hand grenade (the predecessor to the Type 97 hand grenade with a socket on the base for attaching a propellant charge in order to use the grenade as a rifle grenade or mortar projectile). Mercy fires the larger 40mm grenades, similar to the Mk 19 grenade launcher, giving it even more destructive potential with the cost of less ammo per magazine, and in Hardcore mode the ammo is quite heavy. The Single Shotgun is used by members of the Powder Gangers and lower level enemies.

The Great Bear is slightly heavier than the Red Victory (but still lighter than the base Grenade Rifle), but is much more durable and does more damage than the base Grenade Rifle.

This does mean it is effectively a single-shot weapon gameplay-wise, but the large amount of pellets fired and its 12 gauge chambering mean that it is the highest-damage shotgun (and the second highest damage of any weapon) in the game.

Fallout 4 caravan shotgun