What happens if you anneal the same case twice? 

Just a shame we all can't afford one of these annealers eh 🤔

"licensed engineer"

Can you share some data?

As a licensed pilot I agree with the statement the licensed engineer said.

stupid reply. I am an engineer myself, but im not licensed, so i guess im nothing. even then, i wouldnt bring my proffesion into it. and by the way, you certainly mean you are a P.E. which stands for Professional Engineer. Unfortunatly, all that really means is that you studies extra hard, most likely straight out of college, and passed a simple test. Congrats to you. However, most engineers with a few years of experience, are WAY smarter than an engineer that most likely saw ZERO real life engineering scenarios. So, in reality, it means NOTHING. That's why I didn't waist my time perusing a P.E., or as you call it, a professional engineer. Unless you are using the term "professional" in the normal sense, as a person who get paid to do a job. So basically a janitor at a school, for example is a professional janitor. Absolutely not down playing a janitors duties. I could easily chose a beggar at a grocery store, and, again, no harm intended. Nobody likes a name dropper and equally, nobody likes a career dropper. Get a life

At the school of metal working they taught us... Rapid cooling is called a quench. When heated then quenched it is hardened.

I accidentally annealed a bunch of Lapua 6.5CM brass with the wrong (way too low) setting, and now I feel better about going back and doing it with the correct setting!

Please note that the case needs to be cooled down before annealing a second time will have no impact. If you have just pulled it out of the annealer and it is hot and put it back in and immediately apply the same heat setting it will get softer due to it starting at an already high temp. The case should still be ok, however use it as a fouler for that cycle and it should be ok again for the next cycle after it has been sized and shot and re work hardened. (IF there are visible signs of melting however, discard the case)

@@annealingmadeperfect1257 Thanks for the follow-up...No sign of damage and I plan on using it for exactly that...a fouling round. Thanks again.

I’m in the same boat.

We discuss this in part one of our Annealing under the microscope series: www.ampannealing.com/articles/40/annealing-under-the-microscope/ If you scroll down to point 7.

Awesome question and reference to information. Based on your study and conclusion, as I too tumble with SS pins, it creates a ultra thin and almost nickel plated-like hardened surface. Sounds like itll help it from outter wear and scratches without over work hardening and ruining the case… im guessing. This is extreme news to me and I wish more people had access to your data because there are SO many misconceptions!

We have always maintained that annealing before sizing yields the best results.

Most reloaders trim after the sizing process because the cases get stretched after being resized, just check your OAL before and after you run the brass through the sizing die and it is easy to see. The exception would be if you only neck size then you will not see as dramatic of a result as when you FLS.

I also would be interested in your answer to this question. thx.

No, it’s just that back in the old days, technology wasn’t as available for as cheap as it is now. A microscope like the one he has probably costs 75,000-100,000 today, 30 years ago or before it was probably the same price but adjusted for inflation would have cost much more relatively speaking. Plus people just shot and once the case head separated, neck split or primer pocket was blown, you just tossed it out. With modern science we can easily explain what is happening and what causes it.

Interesting question!

We have found no change in hardness with freshly annealed brass with or without quenching. We prefer to let them cool in a rack over several minutes as that way you don't have to dry them off.

It's the stretching of the brass in the die that hardens it (adds energy). The only impact lube should have is to control the sizing action, not change the amount of energy added. I'm guessing if a die is used to significantly change the case dimensions as in making a wildcat case, more energy could be added because you're working the case more. Very interesting presentation

@@John-uo1qf thinking out loud here - but is perhaps more energy absorbed with little or no lube? Certainly there will be some energy released as heat due to more or less friction. Would be interesting to see using his setup.

@@UnCoolDad it would require more force (energy) so yes.

This was my first thought after watching the video. Maybe someone can test that to see if it matters on target. Also, would that second anneal after sizing be “too soft” to properly hold the projectile (less neck “tension”)?

@@steve11b29 I was wondering if it would be the opposite - more neck tension due to the increased springiness. (Or less stiffness) I may have to give this a try - as I am doing my prep at the moment!

I don't know. If you anneal again, it may weaken the "spring back" needed for proper neck tension. It also may not have enough "spring" to aid in extraction if the chamber is dirty/fouled. It may just come down to the caliber/cartridge, action (bolt gun vs semi-auto) and ultimately what one gun/barrel/chamber prefers.

@@Rowrin Indeed. There is a bit more thinking to do here. I don't think it would affect extraction though (bolt action), as it would be work-hardened again after firing.

We recommend annealing before resizing to ensure the brass conforms to the die best.

We don't anneal to a target Temp/time. Those things vary depending on the size of the case. AZTEC analyses the brass by heating it up to a precise melt point and based on the information you put into the annealer beforehand (pilot code and suffix) will apply one of a number of formulas we have created using hardness testing to very in order to create the correct annealing setting.

We have found no change in metallurgy with or without cooling them down in this way.

Why not both 😊