This is the rifle used by Craig Boone and is only obtainable through glitching, by going into a casino and handing over your weapons or console commands. The rifle looks incredibly weathered, its barrel is rusted, and the end of the stock is duct taped on.
The ammunition it uses is magical companion ammo. The ammunition can sometimes be looted from his body if he is killed. The rifle's scope reticule is the same as the sniper rifle's from Fallout 3.
Used by Craig Boone. Although you cannot take it out of his inventory under normal circumstances, entering an area where guns must be handed over to a guard with him as a follower will could add the weapon to your inventory. The weapon can't be used, due to it chambering magical companion ammo, and there is no way to give it back to Boone. Furthermore, if the weapon is dropped, it can not be picked up again.