The science behind annealing brass during the manufacturing of cartridge brass is well-established and very precise. By heating the brass to 750 Deg. F. quickly and removing it from the heat source to cool, it becomes more ductile and less brittle. This process is annealing and when properly done will extend cartridge brass life and improve accuracy.
Test results show brass ductility and carbon buildup affects neck tension.
A little carbon inside your case-necks is advantageous as found by numerous bench rest shooters.
While a heavy buildup of carbon is not desirable a uniform and light coating on the inside of the neck has proven to give better accuracy as opposed to scrubbing inside the case neck with a bore brush until it is bright brass.
Carbon is a natural lubricant. When you have a little bit of carbon inside your case necks, it helps to lubricate the bullets giving a more uniform release upon firing. It can lead to more consistent accuracy.
There are various reports out on annealing cartridge brass. Studies include a report on the general physical properties of cartridge brass, grain structures, ductility, proper temperature annealing and what can cause de-zincification. Variations brands of brass will have different of the brass alloy.
Differences in brands will show variations of case wall thickness, case neck thickness. These variations are easily determined with the Ultimate Cartridge Check System from Cartridgeanneal.com Another is weight variation within a lot. Many precision shooters buy a large lot on one brass then carefully sort by weight. Some may sort by .1 grain others possibly by .5 grs or so depends on the individual. Of course any weight sorting must be done after all case trimming and neck turning is completed.
The science of annealing brass is precise and easily accomplished using the Anneal-Rite unit which guarantees perfect results on every case. By understanding the process and its importance, we can appreciate the actual value of case neck annealing. Brass is strong, durable and found the perfect material for cartridge brass.
Looking for a precise, guaranteed annealing rig go to cartridgeanneal.com see the demonstration video of the unit in operation