How to Anneal Brass Cartridge Cases

Brass, like many other metals, becomes brittle under repeated cold tooling and manipulation. The mouths and shoulders of brass firearms cartridges are subject to this tooling stress when they are reloaded. Unless corrected, tooling stress significantly shortens the safe useful life of a brass cartridge. The effects of the stress can be reversed by the process of annealing, which involves heating the metal to a point slightly above its recrystallization temperature. A nonferrous metal, brass can be quenched, or rapidly cooled in water, without adversely affecting the ductility of the metal.

Things You'll Need

  • Power drill
  • 1/2-inch socket
  • Propane torch
  • Torch igniter
  • Wide-mouthed container, 2-quart capacity
  • Water
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Instructions

    • 1

      Attach the half-inch socket to the power drill. Make sure the socket is deep enough to hold at least half the depth of the cartridge.

    • 2

      Set the propane torch upright on a stable work surface. Place the container, half-filled with water, on the work surface within easy reach.

    • 3

      Light the torch and adjust it to produce an even, blue flame. Insert a cartridge base-first into the half-inch socket.

    • 4

      Run the drill at low speed to slowly rotate the cartridge. Place the mouth of the cartridge into the flame from the torch. Hold the cartridge steady. Be careful not to heat any of the cartridge below the case shoulder. The goal is to evenly heat the circumference of the case mount and shoulder.

    • 5

      Keep the cartridge in the torch flame until the metal around the cartridge mouth and shoulder turns a bluish color. Remove the cartridge from the flame and stop the drill. Drop the cartridge into the container of water to quickly cool the metal. Do not touch the hot cartridge or the socket; dump the cartridge directly from the socket into the water.