Annealing rifle brass is a topic of interest among many rifle shooters who are concerned about accuracy and brass life, but it’s so doggone scary! Just thinking about it makes the average shooter cringe because after all, it involves the weird science of metallurgy and doing something to your brass that you can’t quite explain, and then when you do this thing called annealing, you can’t quite understand how to know if you succeed; after all, you can’t really measure success. And then all that stuff in the forums about color changes, glowing slightly red, tipping cases in water – uggh! It just makes your head hurt because you don’t really know what’s right. (Unless you read the author’s three articles on Case Annealing, which can be found on the Creedmoor Sports Infozone)
Well, In a word, annealing rifle brass is exposing the neck and part of the shoulder of the bottleneck case to enough heat for a period of time to relieve the internal tension (stress) imposed by firing and resizing brass – and just enough before bad changes in the internal makeup (grain structure and strength) occur. And being the discerning shooter that you are, always looking for that competitive edge, you’ve probably started doing research on annealing brass and have found that there are two accessible methods to do so: Propane flame and Induction. Either way, you’ll need to how long to expose the brass to the flame or induction heat, and you found out that you need to do so in a uniform and consistent manner. Not enough heat input and nothing happens – too much heat, and you have caused irreversible damage to the brass. Toss it in the scrap bucket. Now that’s a definite source of anxiety when your Lapua brass is about a buck a round! In order to find the right temperature and time, and to avoid under or overheating, you need access to a metallurgy lab or you will need to use Tempilaq. That is so you will achieve a consistent stress – relief temperature. Well, use of Tempilaq requires patience, and if you are using a propane-based machine, you’ll need a double-dose of patience because the flame intensity changes as time goes by and the torch heats up.
By now, you are wondering if annealing is for you – but you don’t have to be or know a metallurgist. That’s because a New Zealand company called Annealing Made Perfect, or AMP, has done the tedious work of determining how much time and heat is needed to achieve the proper amount of stress relief. And AMP has done that work by measuring microhardness and correlating those measurements to heat input.
Now, enter the AMP machine. The company behind this machine has, for a tremendous variety of calibers and caseheads, determined the amount of heat input needed to achieve the proper stress-relief anneal. And if you can’t find your brass on the long, long list, send them samples and they will get back to you with a machine setting.
So, how do you use this machine? Simply thread in the proper pilot which properly positions the brass in the induction field, select the specified program number, and hit the start button after you insert the brass in the machine; after the seconds-long cycle, you pull the case out and insert your next case. It’s that simple. To change calibers, look up the caliber, and in some cases, the year-specific case head ID, select the program on the machine, and start annealing.
As far as the process of using the AMP machine, you have to handle each and every piece of brass. And so if you have the temperament (you do because you’re a shooter) and time, that’s not a problem, but if you are, say, a service rifle shooter and anneal cases after each firing it could be very time-consuming – a case feeder would be a welcome addition and it’s my understanding that one is on the way.
The machine itself is very solidly-built. The display is bright, setting the machine up is very fast, and the machine is very quiet. Overall, this machine is a pleasure to use. I annealed over 100 223 Rem cases in 30 minutes and look Ma, no Tempilaq, exposed high voltages, or hot flames. Personally, I have gone from the propane age to an induction unit with exposed conductors and induction coil, and have to say that this unit also feels very safe-to-use. So, needless to say, I am all in with the AMP machine.
The only things that could be improved might be the addition of an optional foot pedal to initiate each cycle, and a way to grip the heavy smooth casing when moving it – like carry handles on the sides or one on top – it is a heavy machine and that would make it easier to handle and place in storage, say, under your workbench.
Overall, get this machine if you are serious about achieving the more-than-anecdotal accuracy improvements from annealing – you won’t find anything else out there with greater ease-and simplicity of-operation, repeatability, and technical development behind the machine. This machine gets a solid 10 for technical excellence, solidity, ease-of-use, and the research AMP performed to conceive the basis for this machine by considering every issue associated with case annealing and making annealing practical. Only one other suggestion I would have and that’s to change the name of the machine to AMPP, which would stand for Annealing Made Perfectly Possible.
Knoxville, TN USA