no country for old men , what a shitty ending , the bad guy gets away

@MougyWolf i thought it was an air rifle with some kind of projectile maybe an ice bullet

@FurryFace I think it a steal rod that is very forcefully ejected to a desired length using pressurized air. It is used to penetrate the skull of cattle and smash the brain just before the animal's throat is cut and their blood is drained.