https://sketchfab.com/3d-models/tribal-assault-rifle-57c3afb910b4407cb6b41844aa94df76

A strange makeshift looking assault rifle that seems to have animal bones that are bolted to the gun as well as ropes holding it together this thing seems to have come from the tribes of Utah however no one knows what tribe made it or where they are now the assault rifle uses a hexagonal Screw As a bolt as well as a hammer as well as it seems to use a tubing mechanism to fire despite all it also seems that the magazine is decorated with animal bones as well and closer inspection to the animal bones they seem to be made out of a long extinct thought to be extinct creature known as the Wanamingo that were thought to be killed off by the chosen one in the year 2241 so maybe this weapon predates that year or maybe there are still Wanamingos out there in the wastes either and can be described as High capacity, wild firing rifle. 

this weapon is based off the Primal assault rifle from fortnite https://fortnite.fandom.com/wiki/Primal_Riflehttps://www.nexusmods.com/newvegas/mods/72782Fallout3AdamAdamowiczWanamingo