Why Is Annealing Cartridge Case Brass Necks Important?
When you fire a round, the brass case expands forming a seal to the neck area of the chamber, then when the pressure drops it contracts slightly. This expansion and contraction cause the brass to work-harden. Without neck annealing after numerous firing/reloading cycles the case will fail, normally with a cracked neck. Annealing the neck area of cartridge brass relieves the internal stress making it more ductile, extending its useful life. An added benefit is the neck area will have uniform tension holding the bullet which improves accuracy.
What Is Annealing?
Annealing is a heat treatment process to make metal softer. In the case of cartridge brass this is accomplished by heating to at least 700º F but not over 800º F. then letting it cool. Steel that has been annealed needs to cool very slowly however brass can be naturally air cooled after removing from the heat source. The old for annealing brass was to immediately dunk the case into water once removed from the heat, however, this has no effect on cartridge case brass neck annealing. Proper annealing changes the microstructure of the metal, reducing internal work hardening, the temperature must be controlled and for cartridge case neck annealing must be stopped before reaching dead soft, which will ruin it
Brass used for hunting loads at or close to maximum should be neck annealed at least after 2 firings. Those shooting mild loads possibly after 3 firings. For maximum case life and best consistent neck tension shot to shot annealing after each firing is by far the very best. In addition, annealing your brass can help to improve the accuracy of your rounds. The expansion and contraction resulting from firing/reloading cycles creates work hardening,
How to Anneal Your Brass?
There are several ways to anneal brass, but the most common method is using a torch, most use a propane torch with a pencil flame, The procedure is to heat the brass neck to 750º F then let it air cool.
Enterprise Services, LLC offers a very affordable unit, the Anneal-Rite which guarantees perfect cartridge brass neck annealing. US made it is precise, durable, and affordable. See demonstration video at www.carfridgeanneal.com or call 479 (629-5566) for any questions you may have.
