TO ANNEAL OR NOT TO ANNEAL?
So, you’ve been reloading for a while and have a good supply of brass. Now after 5 to 7 firings you’re seeing brass necks cracking. Premium quality rifle brass is expensive .338 Lapua is about $3.00 ea., .308 Win. $1.00 ea.
You want to extend your brass life and have heard of cartridge case neck annealing. A knowledgeable reloader may have advised he anneals case necks which extends brass life and improves accuracy. This fellow may have cautioned regarding the hazard of annealing the case head as this may cause a rupture blowing out when fired. This can wreck the firearm, possibly injuring the shooter. After hearing this you may have put the idea of annealing case necks out of your mind for a while. As time progressed you may have scrapped your original supply of cases and are again experiencing case failure from cracked necks. When a case is fired and reloaded the neck is moved 3 or 4 times, this results in work hardening, the only cure is neck annealing.
A bench rest shooter who anneals his brass after every firing set an outstanding record with a group less than 1” at 600 yards, the 6 BR brass he used for this record was fired for the 58th time. This represents a dramatic extension of brass life, as well as superb accuracy. By now you may have decided it would be good to at least investigate case neck annealing.
Many years ago, this reloader attempted annealing some brass with unacceptable results. At that time information was almost nil. Instructions were to stand cases up in a pan, add water to 1/3 the depth of the case. This way the head could not be heated above 212º F. & brass begins to anneal at 482º F. The instructions said to heat each case neck with a torch to a low red glow evenly all of the way around and then tip it over into the water. No mention was made as to the proper temperature the case neck needed or what might happen if overheated. With this information annealing was tried with cases standing in a shallow bath of water. A propane torch flame was applied to the case necks. There was no method to measure neck temperature and a number of the .30-06 cases were over heated. After all, if a low red glow is good then a bright red color had to be better, this seemed like good logic right ~ no wrong. By the way what temperature is brass at a low red glow anyway? Years later it was determined a low red glow, even in dim lighting is too hot. All of the cases on hand were annealed in the above manner to a very good red glow. The next reloading these cases were neck sized and many failed with collapsed shoulders. The necks and the top of the shoulders were too soft. Nothing was gained in conservation, just producing scrap brass. At this time cartridge case neck annealing was abandoned.
Years later the sport of high-powered offhand rifle silhouette shooting was of interest and a quantity of 7.62 X 51 brass needed. A good supply of once fired military brass was obtained, some was match brass fired in rifles, others from machine guns which have generous chamber dimensions. It was determined the entire lot of about 1,000 pieces should have the necks annealed.
Research began to obtain precise cartridge brass neck annealing information. It was soon found that cartridge case necks do not have to be quenched in water after they are heated, the water bath only assures case head annealing could not occur. Metallurgists advised water quenching has no significant effect when annealing cartridge brass necks. Cartridge brass is 70 percent copper and 30 percent zinc & annealing starts at 482º F. A cartridge case brass manufacturer stated 700º F. was the low and 800º F. the high to properly anneal cartridge case necks. Once quickly brought to that temperature then air-cooled proper case neck annealing is achieved.
With this information 750º F. became the target neck temperature. Also, the case head had to be kept under 482º to avoid annealing it. This was now the parameters to successfully anneal the case necks.
An infra-red heat measuring gun was investigated to determine temperature. The manufactures advised to obtain accurate readings all brass had to have the same reflective finish with the infra-red gun calibrated to that finish. This would be doable as most serious reloaders clean their brass anyway only requiring inspecting for a uniform finish. The manufacturer of the infra-red heat gun then stated it would not read the brass temperature correctly if the beam was directed through a flame so the heat gun was abandoned. Brass neck annealing occurs rapidly, the necks would be in the annealing flames for only a couple of seconds. Temperature readings had to be instant and accurate, 750 Degree Tempilaq® solved this problem.
There are a few cartridge brass annealing machines on the market costing from about $400.00 to over $1,400.00. A cartridge brass annealer only performs one step in reloading, it did not seem cost effective to invest that much for a tool performing one operation.
A new design was sought; it would have to be efficient, practical and affordable. Invention was in order; a design requirement was a rig that easily positioned a case neck in 2 opposing flames for quick annealing and allowed quick removal when annealing occurred. A prototype was built using a 1" square aluminum block 4" long having a hole bored in each end larger than the outside diameter of the cartridge case head. This design allows a case to slide in and out easily. A hole was cross-drilled in the center of the 4" aluminum bar for an axle. This aluminum bar is now the Cartridge Case Holder. A wooden knob was installed to turn the Cartridge Case Holder by hand as it gets hot acting as a heat sink on the case. In use, a case is inserted clear of the flame, then rotated into and between two opposed propane torch flames impinging on and wrapping around the case neck heating it uniformly. The prototype worked perfectly; production models are now available as the Anneal-Rite. A variety of Cartridge Case Holders are available which accommodate hundreds of different cases from .40 S&W pistol with the largest one taking .50 BMG and even .600 NE. The entire unit with one common size cartridge case holder sells for around a hundred dollars including one bottle of 750 Tempilaq® heat indicating fluid which is guaranteed accurate to +- 7.5º. Annealed cases are processed at 500 to 600 per hour. The Anneal-Rite comes with a money back guarantee assuring perfectly annealed case necks. A demo video can be viewed at www.cartridgeanneal.com. Customer services is available, call 479-629-5566 9am to 9pm Monday through Saturday, you will get a person on the line. You do not have to suffer with premature case failure, or spend Four Hundred to Fourteen Hundred Dollars. This reloader got a 5 shot .620" group at 300 yards using the neck annealed 7.62 X 51 military cases mentioned.
Tom Wilson ©