Reloading Guide
Case Neck Annealing, Explained
If you reload precision rifle brass, annealing is one of the simplest ways to extend case life and tighten your groups. Here is what it is, why it works, and how to do it consistently.
What case neck annealing does
Brass work-hardens. Every firing expands the case and every resizing squeezes it back, and that repeated flexing makes the neck harder and more brittle over time. Eventually the neck grips the bullet inconsistently, and sooner or later it splits. Annealing applies controlled heat to the neck and shoulder to relieve that hardness and return the brass to a softer, more uniform state.
Why handloaders anneal
Two payoffs. First, case life: annealed brass lasts far longer before necks crack, which matters when you are running premium or hard-to-find cases. Second, and more important for accuracy, consistent neck tension. When every case grips the bullet with the same force, your velocity spread shrinks, and lower spread is what holds groups together at long range. This is why annealing is routine for benchrest, PRS, and long-range shooters.
Doing it consistently
The whole game is repeatable heat. Brass neck annealing happens in a narrow window, with most handloaders targeting roughly 650 to 750 degrees Fahrenheit for a short, consistent dwell, often verified with temperature-indicating products. The critical safety rule: heat only the neck and shoulder. If heat reaches the case head and softens it, the case is no longer safe to fire.
This is exactly where a dedicated machine earns its keep. The Bench Source Case Neck Annealing Machine spins each case in place under microprocessor-timed heat, and its fan-cooled aluminum table acts as a heat sink to protect the case head. You set the time once and every case gets the same treatment, which is far more repeatable than torch-by-hand methods.
Frequently asked questions
What is case neck annealing?
Case neck annealing is the controlled heating of the neck and shoulder of a brass cartridge case to relieve the work hardening that builds up from firing and resizing. The heat restores the brass to a softer, more ductile state so it holds the bullet consistently and resists cracking.
Why should I anneal my brass?
Every time you fire and resize a case, the neck gets harder and more brittle. Annealing resets that hardness, which extends case life, keeps neck tension consistent from case to case, and helps prevent neck splits. Consistent neck tension is one of the biggest contributors to lower velocity spread and better accuracy.
How often should I anneal cartridge cases?
Practice varies. Many precision handloaders anneal after every firing to keep neck tension perfectly consistent, while others anneal every two to four firings. The more consistent you want your loads, the more often you anneal.
What temperature should brass be annealed at?
Cartridge brass neck annealing happens in a fairly narrow range, with most handloaders targeting roughly 650 to 750 degrees Fahrenheit for a short dwell time. Temperature-indicating products like Tempilaq are commonly used to confirm you are in range. The goal is to soften the neck and shoulder only, not the case body or head.
Can I over-anneal or ruin my brass?
Yes. Too much heat, or heat that travels down into the case head, can soften the head and make the case unsafe. Never anneal the case head. A purpose-built machine controls heat time precisely and uses a cooled table that acts as a heat sink to protect the case head, which removes most of the guesswork compared to hand methods.
Does annealing improve accuracy?
Indirectly, yes. Annealing does not change the bullet or powder, but by keeping neck tension uniform across every case it reduces a major source of velocity variation. More consistent velocity means tighter groups at distance, which is why annealing is standard practice among long-range and competition shooters.