Junk Rounds

 is a perk in the Fallout: New Vegas add-on Dead Money.

Effects
You can now craft ammo at the reloading bench using alternate materials (scrap metal and tin cans). Specifically, a single round can be made with a single Casing or Hull, 1 Scrap Metal, and 5 Tin Cans.

Behind the scenes
A new ammo subtype, JNK, or Junk rounds, was included in the Dead Money add-on, presumably for use with this perk. The new ammunition type provided the same effects for all calibers: 0.75x to Damage and 1.5x to Gun Condition.

However, the recipes granted by taking the Junk Rounds perk simply produce one round of normal ammunition, rather than of the Junk subtype. JNK-subtype ammunition is not used anywhere in the add-on, and cannot be obtained by normal means.