Annealing of brass in the reloading process alters the physical properties of the case and increases its ductility, making it more workable, and also increases the longevity of the brass so it can be used in more reloading cycles. There are many devices on the market that help the reloader with this process. In this 6.5 Guys weekly gear update we take a close look at the Annealing Made Perfect (AMP) machine. The AMP is one of the newest and most hi-tech on the market today which uses electromagnetic induction and precisely calibrated programs to anneal each case back to the factory specified hardness.
What is induction annealing?
You’ve probably seen an induction stove – the pan gets hot but the cooking surface remains cool. As described by the manufacturer on their website, the AMP machine uses the same process:
“Induction annealing is the process of softening the necks of cases, through heating in an electrically contactless manner. This is achieved through placing the cases within a magnetic field, which induces eddy currents within the brass. Technically, the lower the resistivity of the brass, or the higher the intensity of the magnetic field, the greater are the eddy currents and, consequently, the greater the heating effect. There is no heating element as such; the only thing to get hot is the case. The magnetic field is focused to maximize the eddy currents and heating in the location where it is specifically required (i.e. the neck and shoulder).”
What is unique about the AMP product?
The AMP machine removes the guesswork and calibration efforts associated with traditional machines using propane. AMP provides the user with pre-programmed run times for each specific cartridge as well as pilots (you get three of your choice and additional ones at USD $20 each) to suspend the cartridges properly within the induction coil. The programs take into account the manufacturer of the cartridge case (we all know that each manufacturer’s rendition of a particular cartridge is slightly different) as well as neck turning. Programs and pilots associated with each cartridge are available here and the list is continually updated. If you have a wildcat cartridge that is not on their list, they will make a pilot for you and indicate the proper program.
The programs are not the result of guesswork by the manufacturer. They use a Vickers hardness tester to determine the setting for each cartridge. If you have a cartridge that is not on the list they will test it for free and indicate the proper program. Their research has shown that there is very little lot to lot variation even with cheaper brass. When they have discovered lot to lot variations they indicate so. If you are concerned about any lot to lot variations, they are more than happy to confirm the program if you send them a sample of your brass. You can read more about hardness testing here and watch an informative video here.
AMP machine with selection of pilots
Our personal observations (and why we bought one)
No we didn’t get the machine for free so let’s get that out of the way. This is not a paid endorsement.
Here are the benefits that we realized:
- Complete peace of mind that you are annealing properly – there is no guesswork. With a propane machine you have to calibrate dwell times which can be error prone. Even if you don’t change out your cartridge, dwell times will vary with temperature changes as this affects the propane pressure. Yes you could purchase a regulator but that’s an extra cost.
- We noticed that the AMP machine produces brass that is more like factory brass from a hardness standpoint. Despite all our efforts and research around calibrating our propane machines, brass never returned to factory “softness” and shoulder spring back would increase with each reloading so we had to adjust our sizing dies. Sure, we could have increased the dwell times with the propane machine but then the flame would turn orange indicating that zinc was burning off.
- One of the things we dreaded was setting up our propane machine for different cartridges. With Ed’s OCD he would spend a good 30 minutes making sure everything was perfect. With the AMP machine you simply change out the pilot and select the proper program.
- No need to purchase Tempilaq to maintain calibration.
- You don’t have the fire hazards associated with propane. We also noticed that the propane hoses will fill with oil if you don’t purge them after each use. We noticed this with two different brands of hoses. If you get enough oil in the hoses the flames will sputter and eventually go out.
- There are no consumables outside of electricity. When you switch out propane tanks you also have to recalibrate as each batch of propane has varying mixers of other gasses and impurities and this affects flame temperature and dwell time.
- You can stop in the middle of a batch and come back hours or days later and the results will be consistent across that batch. You can’t say the same with propane if the temperature has changed or you have changed propane tanks.
- The machine is far from fragile. The demo machine that we used had been shipped all around the world to various reviewers and had a noticeable dent on the side. Despite this, the machine worked flawlessly. If you do have a problem, there is a U.S. service center – you don’t have to send it back to New Zealand.
- The machine can be re-programmed when future updates are available.
Here are the drawbacks we encountered:
- You have to insert each case one at a time. However, it didn’t take long to get a rhythm going – it’s not as tedious as you think.
- The machine has a duty cycle and will go into a 30 minute cool down mode. However, Ed got through 400 cases without triggering the cool down mode. Steve triggered the cool down mode only after annealing several hundred larger cases such as .338 Lapua.
In our opinion the benefits far outweigh the drawbacks. Since there is no setup or calibration time required, we can anneal 200 – 300 cases in the same amount of time. If you are annealing multiple calibers the AMP machine is clearly faster as there is no setup time. The biggest benefit is the peace of mind and confidence that the machine imparts. As mentioned earlier, if you want total peace of mind they will test your specific lot of brass and confirm the program for no charge.
So what will this cost me?
The machine retails for USD $995 and includes three pilots of your choice. Additional pilots are USD $20. That sounds like a lot until the consider the cost of kitting out one of the more popular annealing machines with a propane tank, regulator, torch heads, hoses and adapters. For more information please go to the web site at: http://www.ampannealing.com/
Editor: Ed Mobley (firstname.lastname@example.org)